Observations on the Behavior of Cytogenetics and Pollen Development of Alocasia odora (Lindl.) K.Koch

Karyotype,meiotic behavior and pollen development of Alocasia odoras(Lindl.)K.Koch were investigated.The results showed that:(1)The karyotype formula of somatic cell was 2n=28=20 m+8 sm,belonging to Stebbins’s 2A type.The chromosome length was in the range of 7.84-12.08 μm,and the ratios of the long arm to short arms were between of 1.02-2.72.(2)At meiotic metaphase I of pollen mother cells(PMCs),some of the non-homologous chromosomes underwent reciprocal translocation as indicated by ring or chain structures,formed by four,five,six and sometimes up to twelve chromosomes.Quadruples occurred more frequently than other configurations.These demonstrated that the plants of the species were translocation heterozygotes.Mean configurations calculated through five individuals of one population were 5.61Ⅱ⁰+3.72Ⅱ+0.89Ⅳ⁰+0.06Ⅴ+0.78Ⅵ⁰ +0.06Ⅻ,10.38Ⅱ⁰+3.63Ⅱ,9.15Ⅱ⁰+2.85Ⅱ+1Ⅳ⁰,7.76Ⅱ⁰+3.76Ⅱ+1.24Ⅳ⁰,8.52Ⅱ⁰+3.41Ⅱ+1.03Ⅳ⁰,respectively,where Ⅱ⁰,Ⅳ⁰ and Ⅵ⁰ symbolize the rings of bivalent,quadruple and hexadruple.The metaphase I configuration was constant for individual plant but variable among different individuals.(3)Chromosomal bridges and lagging at anaphase I were at a ratio of 15.5% of the observed cells.(4)The mature pollen was spherical and binucleate,and having spinose exine.The ratio of sterile pollen was 9.3%.