Abstract:
The direct, indirect and multiple trait selection on seven quantitative characters of Ginkgo leaves from all over the country, and 86 single tree clones through randomized block experiment (RBE) are studied in this paper.The results of variance analysis show that the heritabilities (h
2) of leaf area index(Lai) and yield(
Y) are 0.7345 and 0.4774, respectively. ΔG′(%) of direct selection ( K =2.06) on Lai, No.leaves/tree(NL) and Yare 81.94%, 29.60% and 26.17%.The results of correlation analysis show that coefficients of genetic correlation (
rg ) of leaf width leaf dry wt.on long shoot (Lw-Ld), leaf width leaf dry wt.on short shoot (Sw-Sd), NL-
Y, and Sw Lw are between 0.5437~0.8306.The correlation heritabilities 〔h(
x, y)〕 of Lw-Ld, Lw-
Y, Lai-
Y, and NL Yare between 0.2506~03669.The direct genetic path coefficients (
PY·i) of NLand Sd→ Yare 0.6890 and 0.2956, respectively, but
PY·iand
rg to Lai→ Yare -0.1510 and 0.4199, respectively.Response to indirect selection (IR) is less than response to direct selection (GS) on ginkgo leaves characters, but direct and indirect selection are best to Lai.The results of index selection show that
riY, E (I) and CGS′ to multiple trait selection including Yare more than single trait and multiple trait selection nonincluding-
Y.Twenty one Large leaf, high yield clones are selected from all over the country 86 clones through index selection, and hereditary gain is more than direct and indirect selection.