印楝无性系当代种子农药品质性状的遗传变异及农药型印楝优株评价

目的]建立一套适合印楝药用优树无性系测定的分析评价方法,并进行农药型印楝优株评价。方法]以印楝药用优树和平均木无性系为试验材料,通过不完全谱系设计建立无性系品比试验,采用重复力估算法在表型水平上对无性系当代种子农药品质性状进行遗传变异分析,提出"农药型印楝"的概念和标准,根据该标准进行农药型印楝优株评价。结果]无性系种子印楝素组分含量随优树种子印楝素组分含量的变化而变化,但在无性系内和无性系间都存在不同程度变异:同一无性系各分株间的印楝素B变异(5.26%37.55%)较印楝素A变异(6.06%15.80%)和印楝素AB变异(2.95%16.14%)大,印楝素B和印楝素AB几乎呈退化和/或趋中遗传倾向,而印楝素A则既有退化和/或趋中遗传倾向又有超母遗传倾向;无性系间种子印楝素组分含量性状具有异质性(P0.01)。无性系印楝素A重复力(0.78)、印楝素B重复力(0.81)和印楝素AB重复力(0.83)均较高,表明无性系间印楝素组分含量的差异主要是由遗传效应和一般环境效应造成的,受特殊环境效应影响较小。按农药型印楝标准,评定LD0505、WW0401、AT0515三个无性系为"农药型印楝品种",LD0505和WW0421是"农药型印楝亲本"。结论]重复力估算法适用于印楝药用优树无性系测定的分析评价,优树种子农药品质性状的遗传传递力强,无性系能保持优树农药品质的优良特性;评定LD0505、WW0401、AT0515为农药型印楝品种,LD0505和WW0421还可作为农药型印楝亲本,其余优树无性系不宜选择。

Genetic Variation of Azadirachtin Quality in Seeds of Neem Clones and Evaluation of Superior Neem Trees for Pesticides

Objective] To evaluate superior trees for pesticides and provide practical methods for assessment of pesticidal neem clones. Method] With azadirachta content in seeds tested, the variety comparative analysis of azadirachta-related phenotypic traits between superior pesticidal neem trees and average control group was performed by incomplete pedigree design, and then the repeat force was calculated to establish the standards of the potential cultivar type "pesticidal neem". Then the superior trees for pesticides were evaluated. Result] The azadirachta content in seeds of clones varied with the azadirachta content in seeds of superior trees. The azadirachta content varied both within and among clones. The variation of azadirachta content in same clone ranged as:azadirachta B (5.26%~37.55%) > azadirachta A (6.06%~15.80%) > azadirachta A+B (2.95%~16.14%). Both the contents of azadirachta B and azadirachta A+B showed degradation and neutrality of genetic predispositions, but the content of azadirachta A showed all genetic predispositions including degradation, neutrality and development. The azadirachta content in seeds of various clones was significantly different (P<0.01).For stability of azadirachta content among superior trees and clones, the coefficient of azadirachta A, B, and A+B was 0.78, 0.81, and 0.83, respectively, indicating that the variance of azadirachta content among clones was mainly influenced by genetic effects and normal environmental effects than some particular environmental effects. According to comprehensive performance of superior tree clones, three clones (LD0505, WW0401, and AT0515) were selected as the "variety of pesticidal neem". LD0505 and WW0421 were "parentage of pesticidal neem". Conclusion] The repeatability of seed azadirachta content could be used to evaluate the quality of superior neem clones, to select variety and parentage of pesticidal neem trees. Analysis results indicates that superior pesticidal features could remain in same clone by genetic heritability. LD0505, WW0401 and AT0515 could be further developed as the varieties of pesticidal neem. Besides, LD0505 and WW0421 could be further developed as parentage of pesticidal neem. Other superior tree clones are unfavorable choice.