Correlation and genetic analysis of seed shell thickness and yield factors in Tartary buckwheat (Fagopyrum tataricum (L.) Gaertn.)

摘要

In order to solve the difficult problem of the outer shell covering in the processing of Tartary buckwheat, weconducted a genetic analysis in segregating F2 and F3 populations derived from a hybrid between ‘YunqiaoNo. 1’ and ‘Rice buckwheat’, and the F3 population was used to analyze the phenotypic and genetic correlationamong the traits. The results showed that the variety with a value of trait for seed shell thickness over 0.20 mmis a hard-shelled type (The thick shell type = seed shell rate 20%), and that with a value of trait for seed shellthickness below 0.15 mm is a easily-shelled type (The thin shell type = seed shell rate 20%), while that witha value of trait for seed shell thickness ranging from 0.15 mm to 0.20 mm is a hard-shelled type or easilyshelledtype. In addition, alleles for traits of number of seed per plant and total seed weight per plant havelarger dominance variance relative to their additive variance, indicating that genes controlling these traits havelarger dominant effects, it is not suitable for the selection of single plant in offspring plants at the early stage ofdevelopment, because these traits do not show up then. The alleles for traits of 1000 kernel weight and seedshell thickness have larger additive variance relative to their dominant variance, indicating that genesgoverning these traits have greater additive effects, with which the single plant can be selected in the progenyat the early stage of development. Although, the value of seed shell thickness has been shown to correlatedpositively with that of 1000 kernel weight, almost all the seeds of easily-shelled type are those with thin shell.However, ideal single plants with easily-shelled trait are those with intermediate phenotypes of seed shellthickness and 1000 kernel weight, by which the traits of large number of seeds per plant and total seed weightper plant could be selected. In the progeny population of this study, there were excellent single plants withhigh-yield and easily-shelled traits, of which the value of seed shell thickness was 0.17 mm (0.15 mm to0.20 mm), the value of 1000 kernel weight was 14 g, the value of number of seeds per plant was 1137 andvalue of total seed weight per plant was 15.9 g. The results showed that taking the hybrid combinations ofeasily-shelled trait with the trait of seed shell thickness was the most effective selection indexes to breed thehigh-yield buckwheat varieties with the trait of easy shelling.