2019 Vol. 37 No. 5
2019, 37(5): 559-568.
DOI: 10.11913/PSJ.2095-0837.2019.50559
Abstract：
We investigated the morphological characteristics and chromosome karyotypes of three local varieties of Lilium brownii var. viridulum (‘Jiangxi’, ‘Pingtou’, and ‘Daye’ lilies) by classical measurements and chromosome routine tableting. Plant morphological analysis indicated that the plant height, flowering diameter, bulb weight and size, scale weight and size in the outer and/or middle layer of bulb, and germination number of scales in ‘Jiangxi’ were significantly larger than those in ‘Daye’ and ‘Pingtou’; furthermore, the leaves of ‘Daye’ were the longest, with a mean value of 14.54 cm. Micromorphological feature analysis revealed that the pollen grains in ‘Jiangxi’ were the largest, with a mean size of 111.76 μm. The leaf epidermis in ‘Pingtou’ showed the longest stomata and the maximum stomata density, with a mean value of 47.6 individual/mm2. In addition, the starch grains in ‘Daye’ were the largest, with an average particle size of 47.61 μm, and the starch grain size distribution in ‘Jiangxi’ was more consistent than that in others. Karyotype analysis showed that the chromosome numbers of the three local varieties were diploid, with the formula 2n=2x=24. The karyotype formula of ‘Jiangxi’ was 2n=2x=24=2m(2SAT) + 6sm(2SAT) + 12st(4SAT) + 4t, of ‘Pingtou’ was 2n=2x=24=4m + 8sm + 10st(4SAT) + 2t, and of ‘Daye’ was 2n=2x=24=2m(2SAT) + 6sm+14st(4SAT) + 2t. All three karyotypes belonged to type 3B.
We investigated the morphological characteristics and chromosome karyotypes of three local varieties of Lilium brownii var. viridulum (‘Jiangxi’, ‘Pingtou’, and ‘Daye’ lilies) by classical measurements and chromosome routine tableting. Plant morphological analysis indicated that the plant height, flowering diameter, bulb weight and size, scale weight and size in the outer and/or middle layer of bulb, and germination number of scales in ‘Jiangxi’ were significantly larger than those in ‘Daye’ and ‘Pingtou’; furthermore, the leaves of ‘Daye’ were the longest, with a mean value of 14.54 cm. Micromorphological feature analysis revealed that the pollen grains in ‘Jiangxi’ were the largest, with a mean size of 111.76 μm. The leaf epidermis in ‘Pingtou’ showed the longest stomata and the maximum stomata density, with a mean value of 47.6 individual/mm2. In addition, the starch grains in ‘Daye’ were the largest, with an average particle size of 47.61 μm, and the starch grain size distribution in ‘Jiangxi’ was more consistent than that in others. Karyotype analysis showed that the chromosome numbers of the three local varieties were diploid, with the formula 2n=2x=24. The karyotype formula of ‘Jiangxi’ was 2n=2x=24=2m(2SAT) + 6sm(2SAT) + 12st(4SAT) + 4t, of ‘Pingtou’ was 2n=2x=24=4m + 8sm + 10st(4SAT) + 2t, and of ‘Daye’ was 2n=2x=24=2m(2SAT) + 6sm+14st(4SAT) + 2t. All three karyotypes belonged to type 3B.
2019, 37(5): 569-571.
DOI: 10.11913/PSJ.2095-0837.2019.50569
Abstract：
Impatiens dalaiensis Gogoi & Borah is reported here as a newly recorded species in China. It is distributed in the Gaoligongshan Nature Reserve in Tengchong County, Yunnan Province, and grows in water ditches under evergreen broad-leaved forest. It differs from other related species by the following characters:flowers verticillate, purple; lower sepal navicular, aristate at mouth; distal lobe of lower petal long-lorate and twisted. The author who published this species stated that the type specimen was collected from India. However, when the type locality GPS latitude and longitude were marked on a map, the site was located in Chayu County, Tibetan Autonomous Region, China. Therefore, we question the type locality information recorded in the original description.
Impatiens dalaiensis Gogoi & Borah is reported here as a newly recorded species in China. It is distributed in the Gaoligongshan Nature Reserve in Tengchong County, Yunnan Province, and grows in water ditches under evergreen broad-leaved forest. It differs from other related species by the following characters:flowers verticillate, purple; lower sepal navicular, aristate at mouth; distal lobe of lower petal long-lorate and twisted. The author who published this species stated that the type specimen was collected from India. However, when the type locality GPS latitude and longitude were marked on a map, the site was located in Chayu County, Tibetan Autonomous Region, China. Therefore, we question the type locality information recorded in the original description.
2019, 37(5): 572-575.
DOI: 10.11913/PSJ.2095-0837.2019.50572
Abstract：
Aspidistra bogneri H.-J. Tillich (Asparagaceae) is reported as a new record in China from the Karst region of Yunnan Province. It was previously known only from the Cuc Phuong National Park, Ninh Binh Province, Vietnam. Detailed characteristic descriptions of this species and color images are provided here. Voucher specimens are stored in the Herbarium of the Kunming Institute of Botany, Chinese Academy of Sciences (KUN).
Aspidistra bogneri H.-J. Tillich (Asparagaceae) is reported as a new record in China from the Karst region of Yunnan Province. It was previously known only from the Cuc Phuong National Park, Ninh Binh Province, Vietnam. Detailed characteristic descriptions of this species and color images are provided here. Voucher specimens are stored in the Herbarium of the Kunming Institute of Botany, Chinese Academy of Sciences (KUN).
2019, 37(5): 576-582.
DOI: 10.11913/PSJ.2095-0837.2019.50576
Abstract：
There are many scattered islands along the coast of Zhejiang in the East China Sea. Among them, the larger islands are often distributed with zonal and stable evergreen broad-leaved forests, which includ Form. Cinnamomum camphora(L.) Presl with different chief compounds (CC), Form. Cyclobalanopsis glauca (Thunb.) Oerst. with different CC, Form. Lithocarpus glaber (Thunb.) Nakai, and Form. Abarema lucida (Benth.) Kosterm. Based on analysis of the vertical structure, we identified 139 dominant and common vascular plant species in the evergreen broad-leaved forests or similar forests in the Zhejiang islands, which showed Tropical Asia, East Asia (especially Sino-Japanese), and Chinese endemic elements for all synusiae from the canopy to the ground layer, including the tree layer, shrub layer, herbaceous layer, and inter-layers. Further analysis of the distributions of 15 Chinese endemic woody species showed that the floristic components were subtropical rather than temperate. In the evergreen broad-leaved forest zones, we identified secondary deciduous broad-leaved forests, which exhibited greater area and different succession stages after the destruction and deforestation of the native vegetation. Thus, secondary forests require protection as it is not clear what stage they belong to in the ecological succession. As such, these forests would be ideal areas for studying secondary succession and restoration ecology. The evergreen broad-leaved forests of the Zhejiang islands are of significance in biodiversity conservation due to their important characters and marine Sino-Japanese floristic elements.
There are many scattered islands along the coast of Zhejiang in the East China Sea. Among them, the larger islands are often distributed with zonal and stable evergreen broad-leaved forests, which includ Form. Cinnamomum camphora(L.) Presl with different chief compounds (CC), Form. Cyclobalanopsis glauca (Thunb.) Oerst. with different CC, Form. Lithocarpus glaber (Thunb.) Nakai, and Form. Abarema lucida (Benth.) Kosterm. Based on analysis of the vertical structure, we identified 139 dominant and common vascular plant species in the evergreen broad-leaved forests or similar forests in the Zhejiang islands, which showed Tropical Asia, East Asia (especially Sino-Japanese), and Chinese endemic elements for all synusiae from the canopy to the ground layer, including the tree layer, shrub layer, herbaceous layer, and inter-layers. Further analysis of the distributions of 15 Chinese endemic woody species showed that the floristic components were subtropical rather than temperate. In the evergreen broad-leaved forest zones, we identified secondary deciduous broad-leaved forests, which exhibited greater area and different succession stages after the destruction and deforestation of the native vegetation. Thus, secondary forests require protection as it is not clear what stage they belong to in the ecological succession. As such, these forests would be ideal areas for studying secondary succession and restoration ecology. The evergreen broad-leaved forests of the Zhejiang islands are of significance in biodiversity conservation due to their important characters and marine Sino-Japanese floristic elements.
2019, 37(5): 583-592.
DOI: 10.11913/PSJ.2095-0837.2019.50583
Abstract：
To understand the community types and structural characteristics of the subtropical evergreen broad-leaved forest in Hongling Mountain, Tianquan County, Sichuan Province, China, we established six 20 m×30 m sample plots between an elevation of 1700 m to 2000 m. We then analyzed species composition, community structure, biomass, and regeneration ability. Results showed that:(1) There were 182 species, belonging to 117 genera and 72 families, which demonstrated the flora characteristics of a typical subtropical evergreen broad-leaved forest; (2) The forest could be classified into three association groups and five associations; (3) The density of the tree layer was 2583-5383 plants/hm2, biomass was 2.42×105-4.26×105 kg/hm2, aboveground biomass of canopy lianas was 1.01×103 kg/hm2, biomass of woody debris (WD) was 1.65×105 kg/hm2, and the forest was secondary forest; (4) Seedlings were abundant, and the species similarity between seedlings and tree species was 88.89%, indicating good natural forest regeneration ability and stabilized community structure. Comprehensive analysis showed that the evergreen broad-leaved forest was dominated by Castanopsis platyacantha formation. Furthermore, although it appears to be a well-preserved secondary forest, further ecological conservation is warranted.
To understand the community types and structural characteristics of the subtropical evergreen broad-leaved forest in Hongling Mountain, Tianquan County, Sichuan Province, China, we established six 20 m×30 m sample plots between an elevation of 1700 m to 2000 m. We then analyzed species composition, community structure, biomass, and regeneration ability. Results showed that:(1) There were 182 species, belonging to 117 genera and 72 families, which demonstrated the flora characteristics of a typical subtropical evergreen broad-leaved forest; (2) The forest could be classified into three association groups and five associations; (3) The density of the tree layer was 2583-5383 plants/hm2, biomass was 2.42×105-4.26×105 kg/hm2, aboveground biomass of canopy lianas was 1.01×103 kg/hm2, biomass of woody debris (WD) was 1.65×105 kg/hm2, and the forest was secondary forest; (4) Seedlings were abundant, and the species similarity between seedlings and tree species was 88.89%, indicating good natural forest regeneration ability and stabilized community structure. Comprehensive analysis showed that the evergreen broad-leaved forest was dominated by Castanopsis platyacantha formation. Furthermore, although it appears to be a well-preserved secondary forest, further ecological conservation is warranted.
2019, 37(5): 593-601.
DOI: 10.11913/PSJ.2095-0837.2019.50593
Abstract：
Tropical mountain rainforest is the dominant vegetation type in Jianfengling, Hainan Island, and is an important part of the terrestrial forest ecosystem. Analysis of the long-term dynamics and influencing factors of litterfall production in Jianfengling could improve our understanding of how tropical forests respond to future climate and environmental changes. Based on a 60 hm2 plot in the tropical mountain rainforest of Jianfengling, we continuously monitored litterfall production using 132 nylon mesh sampling traps from 2013 to 2017. All litterfall products were classified into leaves, branches, and debris to determine the seasonal dynamics and correlation between production and meteorological factors. Results showed that annual litter production ranged from 617.5 to 1084.7 g/m2, with an average production of 768.6 g/m2 per year. Average production of the litterfall products ranked leaves > branches > debris, with 507.9 g/m2, 163.4 g/m2, and 97.3 g/m2 per year, respectively. Leaf litterfall was the dominant component, contributing 66.1% to total litterfall. The seasonal variation pattern of total production was irregular and showed three peaks, whereas litterfall production for each component showed two peaks, although the peak months differed. Total and component litterfall production were influenced by different meteorological factors. Branch litterfall had no significant relationship with any meteorological factor, whereas leaf litterfall was correlated with monthly minimum temperature and average temperature, debris litterfall was correlated with daily maximum temperature, and total litterfall was correlated with average temperature. Therefore, we identified three seasonal peaks in total litter production and determined that the dynamic changes in forest litterfall were influenced by various meteorological factors, especially extreme climate factors.
Tropical mountain rainforest is the dominant vegetation type in Jianfengling, Hainan Island, and is an important part of the terrestrial forest ecosystem. Analysis of the long-term dynamics and influencing factors of litterfall production in Jianfengling could improve our understanding of how tropical forests respond to future climate and environmental changes. Based on a 60 hm2 plot in the tropical mountain rainforest of Jianfengling, we continuously monitored litterfall production using 132 nylon mesh sampling traps from 2013 to 2017. All litterfall products were classified into leaves, branches, and debris to determine the seasonal dynamics and correlation between production and meteorological factors. Results showed that annual litter production ranged from 617.5 to 1084.7 g/m2, with an average production of 768.6 g/m2 per year. Average production of the litterfall products ranked leaves > branches > debris, with 507.9 g/m2, 163.4 g/m2, and 97.3 g/m2 per year, respectively. Leaf litterfall was the dominant component, contributing 66.1% to total litterfall. The seasonal variation pattern of total production was irregular and showed three peaks, whereas litterfall production for each component showed two peaks, although the peak months differed. Total and component litterfall production were influenced by different meteorological factors. Branch litterfall had no significant relationship with any meteorological factor, whereas leaf litterfall was correlated with monthly minimum temperature and average temperature, debris litterfall was correlated with daily maximum temperature, and total litterfall was correlated with average temperature. Therefore, we identified three seasonal peaks in total litter production and determined that the dynamic changes in forest litterfall were influenced by various meteorological factors, especially extreme climate factors.
2019, 37(5): 602-609.
DOI: 10.11913/PSJ.2095-0837.2019.50602
Abstract：
The cDNA sequence of the CyfaSTK gene (GenBank accession number:MH917915.1) was cloned from the flower bud of Cymbidium faberi Rolfe by homologous cloning. Results showed that the gene was 843 bp in length and the open reading frame (ORF) was 705 bp long, encoding a total of 234 amino acids and a stop codon. Molecular phylogenetic analysis and homologous protein comparison showed that the CyfaSTK protein belonged to the transcription factor STK-like evolution line of the AG subfamily of the D-class MADS-box gene family, which contained four distinct domains of MADS, I, K, and C terminal. The C terminal transcriptional activation region contained two conserved motifs:i.e., AG motifⅠ and AG motifⅡ. In addition, there was also a relatively conserved MD motif in Asparagales plants. Tissue specificity analysis showed that the C. faberi CyfaSTK gene was expressed in sepals, petals, lips, anther caps, gynostemia, and ovaries, but not in juvenile leaves. Expression of the C. faberi CyfaSTK gene in the ovary was significantly higher than that in other tissues. Among the dynamic changes in the flower bud at different developmental stages, the expression of CyfaSTK was the highest at the germination stage after dormancy and increased on the day of flowering. These results suggest that the D-class CyfaSTK gene not only regulates organ development in C. faberi, but also plays an important role in the normal development of the gynostemium and ovary.
The cDNA sequence of the CyfaSTK gene (GenBank accession number:MH917915.1) was cloned from the flower bud of Cymbidium faberi Rolfe by homologous cloning. Results showed that the gene was 843 bp in length and the open reading frame (ORF) was 705 bp long, encoding a total of 234 amino acids and a stop codon. Molecular phylogenetic analysis and homologous protein comparison showed that the CyfaSTK protein belonged to the transcription factor STK-like evolution line of the AG subfamily of the D-class MADS-box gene family, which contained four distinct domains of MADS, I, K, and C terminal. The C terminal transcriptional activation region contained two conserved motifs:i.e., AG motifⅠ and AG motifⅡ. In addition, there was also a relatively conserved MD motif in Asparagales plants. Tissue specificity analysis showed that the C. faberi CyfaSTK gene was expressed in sepals, petals, lips, anther caps, gynostemia, and ovaries, but not in juvenile leaves. Expression of the C. faberi CyfaSTK gene in the ovary was significantly higher than that in other tissues. Among the dynamic changes in the flower bud at different developmental stages, the expression of CyfaSTK was the highest at the germination stage after dormancy and increased on the day of flowering. These results suggest that the D-class CyfaSTK gene not only regulates organ development in C. faberi, but also plays an important role in the normal development of the gynostemium and ovary.
2019, 37(5): 610-620.
DOI: 10.11913/PSJ.2095-0837.2019.50610
Abstract：
The transcription factors of the bHLH family have important regulatory effects on plant growth and development. Here, Phyllostachys edulis (Carr.) Lehaie was used as experimental material to understand the characteristics of bHLH family members in bamboo and explore their expression patterns under adverse conditions. Bioinformatics were used to identify and systematically analyze the bHLH family members at the genomic level, and their expression patterns in different tissues and expression of several bHLH genes under high salt and drought stress conditions were further analyzed. Our results identified 153 bHLH transcription factor genes (PebHLH001-PebHLH153) with complete conserved domains in Ph. edulis. The number of introns in PebHLHs ranged from 0 to 14. The drought and salt stress related cis-acting elements were found in the promoters of 137 PebHLHs. The length of the proteins encoded by PebHLHs ranged from 134 aa (PebHLH005) to 1401 aa (PebHLH083) with molecular weights of 13.4 to 152.6 kD, respectively. Based on phylogenetic analysis of bHLHs in Ph. edulis and Oryza sativa L., 153 PebHLHs were clustered into 17 subgroups, with the C subgroup containing the highest number (42). According to expression profile analysis of transcriptome data, 151 PebHLHs exhibited different expression levels in different tissues and growth stages of Ph. edulis. Real-time quantitative polymerase chain reaction (PCR) showed that 14 PebHLHs were up-regulated and two PebHLHs were down-regulated after drought stress, whereas 13 were up-regulated and three were down-regulated after salt stress. However, there were some differences in the expression patterns of 16 PebHLHs, indicating that they may play different roles in response to drought and salt stress.
The transcription factors of the bHLH family have important regulatory effects on plant growth and development. Here, Phyllostachys edulis (Carr.) Lehaie was used as experimental material to understand the characteristics of bHLH family members in bamboo and explore their expression patterns under adverse conditions. Bioinformatics were used to identify and systematically analyze the bHLH family members at the genomic level, and their expression patterns in different tissues and expression of several bHLH genes under high salt and drought stress conditions were further analyzed. Our results identified 153 bHLH transcription factor genes (PebHLH001-PebHLH153) with complete conserved domains in Ph. edulis. The number of introns in PebHLHs ranged from 0 to 14. The drought and salt stress related cis-acting elements were found in the promoters of 137 PebHLHs. The length of the proteins encoded by PebHLHs ranged from 134 aa (PebHLH005) to 1401 aa (PebHLH083) with molecular weights of 13.4 to 152.6 kD, respectively. Based on phylogenetic analysis of bHLHs in Ph. edulis and Oryza sativa L., 153 PebHLHs were clustered into 17 subgroups, with the C subgroup containing the highest number (42). According to expression profile analysis of transcriptome data, 151 PebHLHs exhibited different expression levels in different tissues and growth stages of Ph. edulis. Real-time quantitative polymerase chain reaction (PCR) showed that 14 PebHLHs were up-regulated and two PebHLHs were down-regulated after drought stress, whereas 13 were up-regulated and three were down-regulated after salt stress. However, there were some differences in the expression patterns of 16 PebHLHs, indicating that they may play different roles in response to drought and salt stress.
2019, 37(5): 621-627.
DOI: 10.11913/PSJ.2095-0837.2019.50621
Abstract：
Five harvest indices of ‘Jintao’ kiwifruit (Actinidia chinensis Planch.) from 27 orchards in Henan Province were measured, including average fruit weight, hue angle, firmness, soluble solids content (SSC), and dry matter. Eight fruit quality parameters were measured at the mature stage, including average fruit weight, hue angle, firmness, SSC, total sugar (TS), titratable acids (TA), ratio of TS/TA, and proportion of ripening fruit (PRF). A comprehensive score of fruit quality for each orchard was obtained through principal component analysis based on the eight fruit quality parameters. The correlations between harvest indices and comprehensive score and other fruit quality parameters were analyzed. Results showed that all harvest indices were significantly associated with the comprehensive score, with the highest correlation coefficient found for dry matter (r=0.437). Dry matter was also significantly correlated with three other fruit quality traits, including SSC, total sugar and TS/TA, with correlation coefficients of 0.578, 0.324 and 0.279, respectively. Hue angle was significantly correlated with the proportion of mature fruits. Dry matter was the main index for evaluating fruit quality in the ‘Jintao’, followed by SSC and hue angle.
Five harvest indices of ‘Jintao’ kiwifruit (Actinidia chinensis Planch.) from 27 orchards in Henan Province were measured, including average fruit weight, hue angle, firmness, soluble solids content (SSC), and dry matter. Eight fruit quality parameters were measured at the mature stage, including average fruit weight, hue angle, firmness, SSC, total sugar (TS), titratable acids (TA), ratio of TS/TA, and proportion of ripening fruit (PRF). A comprehensive score of fruit quality for each orchard was obtained through principal component analysis based on the eight fruit quality parameters. The correlations between harvest indices and comprehensive score and other fruit quality parameters were analyzed. Results showed that all harvest indices were significantly associated with the comprehensive score, with the highest correlation coefficient found for dry matter (r=0.437). Dry matter was also significantly correlated with three other fruit quality traits, including SSC, total sugar and TS/TA, with correlation coefficients of 0.578, 0.324 and 0.279, respectively. Hue angle was significantly correlated with the proportion of mature fruits. Dry matter was the main index for evaluating fruit quality in the ‘Jintao’, followed by SSC and hue angle.
2019, 37(5): 628-636.
DOI: 10.11913/PSJ.2095-0837.2019.50628
Abstract：
To investigate the influence of leaf form on the relationship between water and photosynthesis of leaves and branches, we measured the stomatal conductance, leaf water conductance, water potential, and relative water content of 11 compound-leafed species and six simple-leafed species in Fabaceae. Results showed no significant differences in midday water potential between leaf rachises (-0.91 MPa) of compound-leafed trees and branches of simple-leafed trees (-0.88 MPa). However, the midday water potential of the branches of compound-leafed trees (-0.60 MPa) was significantly higher than that of simple-leafed trees. The percent decrease in midday stomatal conductance of compound-leafed trees was significantly higher than that of simple-leafed trees (55.3% vs. 34.1%). We found significantly positive correlations between leaf and stem midday water potentials in all 17 species, and between the rachis and stem midday water potentials in the 11 compound-leafed species. There was no correlation between midday water potential of leaflets, leaf rachises, and branches and midday stomatal conductance. There was a significant positive correlation between leaf hydraulic conductance and midday stomatal conductance across the 17 species (r=0.79, P<0.001), and a significant negative correlation between leaf hydraulic conductance and percent decrease in midday stomatal conductance (r=-0.81, P<0.001), indicating the important role of leaf hydraulic conductance in maintaining diurnal stomatal conductance. There were significant differences in the photosynthesis-water relationship among simple-and compound-leafed tree species, reflecting their different adaptive strategies to environmental conditions.
To investigate the influence of leaf form on the relationship between water and photosynthesis of leaves and branches, we measured the stomatal conductance, leaf water conductance, water potential, and relative water content of 11 compound-leafed species and six simple-leafed species in Fabaceae. Results showed no significant differences in midday water potential between leaf rachises (-0.91 MPa) of compound-leafed trees and branches of simple-leafed trees (-0.88 MPa). However, the midday water potential of the branches of compound-leafed trees (-0.60 MPa) was significantly higher than that of simple-leafed trees. The percent decrease in midday stomatal conductance of compound-leafed trees was significantly higher than that of simple-leafed trees (55.3% vs. 34.1%). We found significantly positive correlations between leaf and stem midday water potentials in all 17 species, and between the rachis and stem midday water potentials in the 11 compound-leafed species. There was no correlation between midday water potential of leaflets, leaf rachises, and branches and midday stomatal conductance. There was a significant positive correlation between leaf hydraulic conductance and midday stomatal conductance across the 17 species (r=0.79, P<0.001), and a significant negative correlation between leaf hydraulic conductance and percent decrease in midday stomatal conductance (r=-0.81, P<0.001), indicating the important role of leaf hydraulic conductance in maintaining diurnal stomatal conductance. There were significant differences in the photosynthesis-water relationship among simple-and compound-leafed tree species, reflecting their different adaptive strategies to environmental conditions.
2019, 37(5): 637-643.
DOI: 10.11913/PSJ.2095-0837.2019.50637
Abstract：
Ottelia cordata (Wall.) Dandy, a species with heteromorphic leaves during growth and development, was used as the study material. Chlorophyll fluorescence and pH-drift were used to measure chlorophyll fluorescence characteristics and HCO3- utilization capability of different shaped leaves of O. cordata:i.e., submerged leaves (S), floating leaves (F), submerged floating leaves (SF), and floating leaves only (OF). Rapid light curve (RLC) results showed that the relative electron transport rate (rETR) of submerged leaves (S) was significantly lower than that of the other leaves, and the gap increased with light intensity; photochemical fluorescence quenching (qP), maximum rETR (rETRmax), and light-saturation coefficient (Ek) of submerged leaves (S) were also significantly lower than that of floating leaves (F). The CT/Alk value of submerged leaves (S), which can show HCO3- utilization capability, was significantly lower than that of both types of floating leaves (F and OF). These results indicated that the mature floating leaves (F) of O. cordata had higher photosynthetic efficiency than juvenile submerged leaves (S), and floating leaves (F) were more adapted to high light. These results also suggest that submerged floating leaves (SF) can enhance HCO3- utilization capability to adapt to low CO2 in water.
Ottelia cordata (Wall.) Dandy, a species with heteromorphic leaves during growth and development, was used as the study material. Chlorophyll fluorescence and pH-drift were used to measure chlorophyll fluorescence characteristics and HCO3- utilization capability of different shaped leaves of O. cordata:i.e., submerged leaves (S), floating leaves (F), submerged floating leaves (SF), and floating leaves only (OF). Rapid light curve (RLC) results showed that the relative electron transport rate (rETR) of submerged leaves (S) was significantly lower than that of the other leaves, and the gap increased with light intensity; photochemical fluorescence quenching (qP), maximum rETR (rETRmax), and light-saturation coefficient (Ek) of submerged leaves (S) were also significantly lower than that of floating leaves (F). The CT/Alk value of submerged leaves (S), which can show HCO3- utilization capability, was significantly lower than that of both types of floating leaves (F and OF). These results indicated that the mature floating leaves (F) of O. cordata had higher photosynthetic efficiency than juvenile submerged leaves (S), and floating leaves (F) were more adapted to high light. These results also suggest that submerged floating leaves (SF) can enhance HCO3- utilization capability to adapt to low CO2 in water.
2019, 37(5): 644-652.
DOI: 10.11913/PSJ.2095-0837.2019.50644
Abstract：
To evaluate the application potential of two new seed lotus(Nelumbo nucifera Gaertn.) cultivars (‘WBG_S1’ and ‘WBG_S2’), their seed yield and nutritional traits were compared with those of 12 main cultivated varieties. The nutritional trait indexes of different cultivars were subsequently evaluated by membership-function analysis. Results showed significant differences in seed yield and nutritional quality. There were significant differences in soluble sugar and starch content at different developmental stages in a single cultivar. Compared with the mature seeds, fresh seeds had significantly higher soluble sugar content but significantly lower protein and starch content (P<0.05). Generally, compared to the 12 main cultivated varieties, ‘WBG_S1’ and ‘WBG_S2’ had better yield and nutritional qualities. ‘WBG_S1’ exhibited high yield and high starch content in the mature seeds, reaching up to 52.15%. Thus, it is a good cultivar for producing natural starch products. ‘WBG_S2’ had low amylose and amylopectin content, but high soluble sugar content of up to 23.43% in fresh seeds. Thus, its seeds are suitable for fresh eating. In this study, membership-function analysis was used for the first time to evaluate the nutritional traits of lotus seeds and provides a scientific basis for the validation of lotus seed quality. This study also provides theoretical evidence for the application of the two new cultivars ‘WBG_S1’ and ‘WBG_S2’.
To evaluate the application potential of two new seed lotus(Nelumbo nucifera Gaertn.) cultivars (‘WBG_S1’ and ‘WBG_S2’), their seed yield and nutritional traits were compared with those of 12 main cultivated varieties. The nutritional trait indexes of different cultivars were subsequently evaluated by membership-function analysis. Results showed significant differences in seed yield and nutritional quality. There were significant differences in soluble sugar and starch content at different developmental stages in a single cultivar. Compared with the mature seeds, fresh seeds had significantly higher soluble sugar content but significantly lower protein and starch content (P<0.05). Generally, compared to the 12 main cultivated varieties, ‘WBG_S1’ and ‘WBG_S2’ had better yield and nutritional qualities. ‘WBG_S1’ exhibited high yield and high starch content in the mature seeds, reaching up to 52.15%. Thus, it is a good cultivar for producing natural starch products. ‘WBG_S2’ had low amylose and amylopectin content, but high soluble sugar content of up to 23.43% in fresh seeds. Thus, its seeds are suitable for fresh eating. In this study, membership-function analysis was used for the first time to evaluate the nutritional traits of lotus seeds and provides a scientific basis for the validation of lotus seed quality. This study also provides theoretical evidence for the application of the two new cultivars ‘WBG_S1’ and ‘WBG_S2’.
2019, 37(5): 653-661.
DOI: 10.11913/PSJ.2095-0837.2019.50653
Abstract：
Calligonum roborowskii A. Los. is an endemic species distributed only in the desert environments of northwest (Gansu and Xinjiang provinces) China. The achene fruit of this species is covered in oval bristles, with dispersal and seed germination occurring from intact achene fruit. In this paper, we investigated the effects of these bristles on dispersal, water absorption and dehydration, and fruit germination both in the field and laboratory. Results showed that there were significant differences in fruit color, size, weight, and length of bristle hairs at different storage time. The amount of time the bristled fruit floated on the surface of water and the water diffusion capacity associated with the amount of water absorption were greater than that for the non-bristled fruit. The diffusion distances of intact fruit at 1 m/s and 4 m/s wind speed were longer than that of non-bristled fruit. In addition, significant differences were found in the germination rates of bristled and non-bristled fruits under 20℃/30℃ and light-dark conditions, 10 mmol/L of AG3, and different dry storage time; specifically, the germination rate of fruits without bristles was higher than that of intact fruits in each treatment. Outdoor potted experiments show that the fruit bristles of this species have an inhibitory effect on seed germination. However, the fruit bristles have an important effect on the dispersal and germination characteristics of this species and on population renewal in the environments on the edge of the Taklamakan Desert.
Calligonum roborowskii A. Los. is an endemic species distributed only in the desert environments of northwest (Gansu and Xinjiang provinces) China. The achene fruit of this species is covered in oval bristles, with dispersal and seed germination occurring from intact achene fruit. In this paper, we investigated the effects of these bristles on dispersal, water absorption and dehydration, and fruit germination both in the field and laboratory. Results showed that there were significant differences in fruit color, size, weight, and length of bristle hairs at different storage time. The amount of time the bristled fruit floated on the surface of water and the water diffusion capacity associated with the amount of water absorption were greater than that for the non-bristled fruit. The diffusion distances of intact fruit at 1 m/s and 4 m/s wind speed were longer than that of non-bristled fruit. In addition, significant differences were found in the germination rates of bristled and non-bristled fruits under 20℃/30℃ and light-dark conditions, 10 mmol/L of AG3, and different dry storage time; specifically, the germination rate of fruits without bristles was higher than that of intact fruits in each treatment. Outdoor potted experiments show that the fruit bristles of this species have an inhibitory effect on seed germination. However, the fruit bristles have an important effect on the dispersal and germination characteristics of this species and on population renewal in the environments on the edge of the Taklamakan Desert.
2019, 37(5): 662-671.
DOI: 10.11913/PSJ.2095-0837.2019.50662
Abstract：
We selected three different functional groups of leguminous tree seedlings from a 60 hm2 sample plot of tropical mountain rainforest in Jianfengling, Hainan, China, as the study objects. The three leguminous trees included Ormosia balansae Drake, Ormosia semicastrata Hance f. litchifolia How, and Archidendron clypearia (Jack) I. C. Nielsen, with low, medium, and high nitrogen (N) demands, respectively. We conducted a soil nutrient control experiment in a greenhouse and compared growth performance of the three leguminous plant seedlings under five N and two phosphorus (P) addition concentration gradients. Results showed that:(1) Under N enrichment, the sensitivities of the five indicators, i.e., seedling height, total leaf area, total root length, root surface area, and biomass, to medium and high N addition were in the order of O. balansae > A. clypearia > O. semicastrata f. litchifolia. Additionally, total leaf area was the most sensitive index to changes in soil N concentration, followed by total root length and root surface area of O. semicastrata f. litchifolia seedlings as well as total root length of A. clypearia seedlings. (2) The root shoot ratio of O. semicastrata f. litchifolia and A. clypearia seedlings was relatively unaffected by N addition. In contrast, the root shoot ratio of O. semicastrata f. litchifolia seedlings increased markedly with the increase in N concentration, implying that O.semicastrata f. litchifolia had a greater tolerance to medium and high soil N concentrations. (3) Under P enrichment, O. balansae and A. clypearia seedlings showed a greater growth rate under low than high P addition, indicating low N and low P demand for these two species at the seedling stage. However, O. semicastrata f. litchifolia seedlings grew faster with high P and low N treatment, thus suggesting low N and high P demand at the seedling stage.
We selected three different functional groups of leguminous tree seedlings from a 60 hm2 sample plot of tropical mountain rainforest in Jianfengling, Hainan, China, as the study objects. The three leguminous trees included Ormosia balansae Drake, Ormosia semicastrata Hance f. litchifolia How, and Archidendron clypearia (Jack) I. C. Nielsen, with low, medium, and high nitrogen (N) demands, respectively. We conducted a soil nutrient control experiment in a greenhouse and compared growth performance of the three leguminous plant seedlings under five N and two phosphorus (P) addition concentration gradients. Results showed that:(1) Under N enrichment, the sensitivities of the five indicators, i.e., seedling height, total leaf area, total root length, root surface area, and biomass, to medium and high N addition were in the order of O. balansae > A. clypearia > O. semicastrata f. litchifolia. Additionally, total leaf area was the most sensitive index to changes in soil N concentration, followed by total root length and root surface area of O. semicastrata f. litchifolia seedlings as well as total root length of A. clypearia seedlings. (2) The root shoot ratio of O. semicastrata f. litchifolia and A. clypearia seedlings was relatively unaffected by N addition. In contrast, the root shoot ratio of O. semicastrata f. litchifolia seedlings increased markedly with the increase in N concentration, implying that O.semicastrata f. litchifolia had a greater tolerance to medium and high soil N concentrations. (3) Under P enrichment, O. balansae and A. clypearia seedlings showed a greater growth rate under low than high P addition, indicating low N and low P demand for these two species at the seedling stage. However, O. semicastrata f. litchifolia seedlings grew faster with high P and low N treatment, thus suggesting low N and high P demand at the seedling stage.
2019, 37(5): 672-681.
DOI: 10.11913/PSJ.2095-0837.2019.50672
Abstract：
Iris comprises approximately 280 species with variable floral traits, which makes it an ideal genus for scientific and horticultural research. Although some irises are capable of selfing and clonal reproduction, pollinator-mediated outcrossing still plays an important role in species maintenance and genetic diversity. However, pollinator attraction and outcrossing strategies in Iris have yet to be systematically summarized. In this paper, we describe the pollinator diversity and floral architecture adaptations for animal pollination in irises. On this basis, we introduce how visual and olfactory signals and floral rewards (eg., pollen, nectar, and heat) are presented in Iris to attract pollinators. Before and after pollinator visitation, Iris plants can promote outcrossing by regulating their floral display, spatiotemporal isolation of male and female functions, and post-pollination processes. Furthermore, third-party factors like florivores and resource allocations need to be considered in studies on pollinator attraction and outcrossing in Iris. Future research should focus on hot or controversial issues with the use of advanced techniques like quantitative measurement of floral signals and molecular detection of outcrossing rates, and on large-scale comparison of the modes of plant-pollinator interactions and outcrossing strategies in Iris species.
Iris comprises approximately 280 species with variable floral traits, which makes it an ideal genus for scientific and horticultural research. Although some irises are capable of selfing and clonal reproduction, pollinator-mediated outcrossing still plays an important role in species maintenance and genetic diversity. However, pollinator attraction and outcrossing strategies in Iris have yet to be systematically summarized. In this paper, we describe the pollinator diversity and floral architecture adaptations for animal pollination in irises. On this basis, we introduce how visual and olfactory signals and floral rewards (eg., pollen, nectar, and heat) are presented in Iris to attract pollinators. Before and after pollinator visitation, Iris plants can promote outcrossing by regulating their floral display, spatiotemporal isolation of male and female functions, and post-pollination processes. Furthermore, third-party factors like florivores and resource allocations need to be considered in studies on pollinator attraction and outcrossing in Iris. Future research should focus on hot or controversial issues with the use of advanced techniques like quantitative measurement of floral signals and molecular detection of outcrossing rates, and on large-scale comparison of the modes of plant-pollinator interactions and outcrossing strategies in Iris species.
2019, 37(5): 682-689.
DOI: 10.11913/PSJ.2095-0837.2019.50682
Abstract：
Stem cells are a group of pluripotent cells that can differentiate into a diverse range of specialized cell types. They continuously provide new cells for organogenesis, wound repair, and regeneration in multicellular organisms. Stem cell specification and differentiation are orchestrated by complex gene regulatory networks. In addition, epigenetic regulation plays a crucial role in many biological events, including stem cell determination. In this review, we summarize recent advances in epigenetic control of root stem cells in the model plant Arabidopsis thaliana. Specifically, we focus on the interplay between epigenetic regulators and stem cell-controlling key transcription factors, which regulates root stem cell self-renewal and differentiation in plants.
Stem cells are a group of pluripotent cells that can differentiate into a diverse range of specialized cell types. They continuously provide new cells for organogenesis, wound repair, and regeneration in multicellular organisms. Stem cell specification and differentiation are orchestrated by complex gene regulatory networks. In addition, epigenetic regulation plays a crucial role in many biological events, including stem cell determination. In this review, we summarize recent advances in epigenetic control of root stem cells in the model plant Arabidopsis thaliana. Specifically, we focus on the interplay between epigenetic regulators and stem cell-controlling key transcription factors, which regulates root stem cell self-renewal and differentiation in plants.
2019, 37(5): 690-698.
DOI: 10.11913/PSJ.2095-0837.2019.50690
Abstract：
Abscisic acid (ABA) is an important plant phytohormone and plays a key role in the regulation of seed development, dormancy, and germination, plant growth and flowering inhibition, and abiotic stress response pathways. ABA also interacts with other plant hormones, such as auxin and ethylene, to precisely regulate root growth, including that of preprimary roots, lateral roots, and root hairs. In this updated review, we summarize the molecular mechanisms by which ABA regulates plant root growth and development, focusing on the model plant Arabidopsis thaliana (L.) Heynh. We also discuss the proposed mechanism of ABA interaction with other plant hormones (such as GA) to regulate root growth, especially under abiotic stress conditions. Additionally, the future research directions in this field are discussed.
Abscisic acid (ABA) is an important plant phytohormone and plays a key role in the regulation of seed development, dormancy, and germination, plant growth and flowering inhibition, and abiotic stress response pathways. ABA also interacts with other plant hormones, such as auxin and ethylene, to precisely regulate root growth, including that of preprimary roots, lateral roots, and root hairs. In this updated review, we summarize the molecular mechanisms by which ABA regulates plant root growth and development, focusing on the model plant Arabidopsis thaliana (L.) Heynh. We also discuss the proposed mechanism of ABA interaction with other plant hormones (such as GA) to regulate root growth, especially under abiotic stress conditions. Additionally, the future research directions in this field are discussed.
