甘蔗家系农艺性状遗传力分析

Heritability analysis of agronomic traits in sugarcane families

【目的】了解甘蔗亲本农艺性状的遗传特点,为甘蔗亲本选择和杂交组合配制提供参考和指导。【方法】对2008~2014年17组甘蔗家系试验的参试亲本及组合主要农艺性状进行调查,并采用3种不同方差分解方法对其农艺性状的遗传方差比率和遗传力进行分析。【结果】甘蔗不同农艺性状的遗传方差比率、加性遗传方差比率和遗传力在不同试验间表现不同。茎径和锤度是遗传方差比率、加性遗传方差比率和遗传力较高的性状;蔗茎产量和蔗糖产量是遗传方差比率、加性遗传方差比率和遗传力较低的性状;有效茎数的遗传方差比率、加性遗传方差比率和遗传力属中等;株高是遗传力中等、加性遗传方差比率最低的性状。对于不同分析方法,在分别计算时采用固定模型计算的参数值最高,随机模型最低,随机＋家系比随机模型略高;在联合计算时,采用随机＋家系计算的参数值最高,固定模型最低,而随机模型的参数值高于固定模型。【结论】数据进行联合分析时宜选用随机＋家系分析方法,通过增加家系信息,可明显提高分析精度;甘蔗主要农艺性状遗传方差比率、加性遗传方差比率和遗传力均受性状及试验的影响;在亲本及后代按不同原则和标准对蔗茎产量和蔗糖产量、茎径和锤度、株高、有效茎数等性状进行选择,可提高选择效率。

【Objective】The present study was conducted to understand the genetic characteristics of agronomic traits of sugarcane parents in order to provide references and guidances for breeding parent selection and sugarcane cross design.【Method】The main agronomic traits of tested sugarcane parents and crosses were investigated in 17 family tests during2008-2014,and their genetic variance proportion and heritability of traits were analyzed by using three different variance decomposition methods viz., fixed model, random model and random＋family. 【Result】Three parameters, namely, genetic variance proportion, additive genetic variance proportionand heritability of trait were different among different traits or family tests. The stalk diameter and brix of sugarcane had higher value of these three parameters, while the cane yield and sugar yield had lower value. The number of millable cane was in moderate level for these three parameters. The heritability of plant height was in moderate, but its additive genetic variance proportion found to be the lowest. As to different analysis methods, the above-mentioned parameter values of fixed model presented the highest when used separated calculation,those of random model were the lowest, and those of random ＋family model were higher than random model. When used combined calculation for all family tests, the above-mentioned parameter values of random＋family model found to be the highest, fixed model found to be the lowest, and random model found to be higher than fixed model. 【Conclusion】As to data combined calculation analysis, the random＋family model is the best selection method, and the accuracy of analysis could be improved significantly by increasing the pedigree information. For trait selection in breeding program, the cane yield, sugar yield,stalk diameter and brix, plant height and number of millable cane for sugarcane parents and progeny should be selected according to different principles and standards.