木薯自交后代疫霉根腐病抗性评价及抗性材料遗传多样性分析

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Abstract： The excised root tissue inoculation method was used to evaluate resistance to cassava root rot caused by Phytophthora in137 inbred progen GR891 cassava samples. Genetic diversity analysis，including the coefficient of variation and genetic diversity indices，was conducted on 93 samples exhibiting high or moderate resistance at 10key agronomic traits.Results showed that among the 137 samples，56 exhibited high resistance 1 （40.88% ），37 showed resistance （27.01% ），33 were moderately susceptible （24.09%） ），9 were susceptible 1 （6.57%） ，and2were highly susceptible （ 1.46% ）.In the 93 resistant samples，the coefficients of variation for10 main agronomic traitsranged from 14.46% to 77.63% ，with genetic diversity indices between 0.60 and 2.04， indicating abundant genetic variation in the resistant progeny of GR891. Correlation analysis revealed three pairs of traits with highly significant correlations and three pairs with significant correlations.Fresh tuber weight per plant was significantly positively correlated with stem diameter and tuber number per plant，with correlation coefficientsof 0.490 and 0.680，respectively.Principal component analysis identified plant height，stem thickness，main stem height，tuber number per plant，and fresh tuber weight per plant as the primary features of phenotypic variation in cassava，with the cumulative contribution rate of the three principal components reaching 74.52% . Cluster analysis suggested three major categories： Category I，including 7 materials which have relatively poor performance at traits；Category II，characterized by superior overall traits with outstanding performance in yield traits and disease resistance，showing high potential for utilizationand including 4 materials；and Category III，comprising 82 materials，with Subgroup IIa exhibiting good traits and disease resistance as well as significant potential for high yield，including 9 materials.This study provides scientific evidence for selecting cassava germplasm resistant to Phytophthora root rot and informs genetic analysis for resistance traits.

Key words： GR891 cassava;inbred progeny;root rot disease;resistance evaluation

木薯（ManihotesculentaCrantz）为大戟科木薯属灌木状多年生作物，块根富含淀粉，与马铃薯、甘薯并列为世界三大薯类，既是重要的粮食作物，也是广泛应用的工业原料。（剩余16924字）