甘蔗种质资源蔗糖分性状遗传变异分析及高糖种质发掘

Genetic Variation of Sucrose Content and Exploration of High Sugar Genotypes in Sugarcane Germplasm

高糖种质是甘蔗高糖育种取得成功的物质基础,性状遗传变异的评估是提高遗传改良效率的重要内容。本研究以292份国内外甘蔗品种资源为研究材料,通过3年(1年新植2年宿根)系统的田间试验,对蔗糖分的方差和遗传参数(遗传方差、广义遗传力、变异系数等)进行了分析和评估。结果显示,种质间蔗糖分性状差异极显著,但与年份间的互作效应不显著,具有较高的广义遗传力(3年试验的广义遗传力为0.85)。变异系数分析显示,尽管具有较大的极差(平均为10.66%),但变异系数相对较小(平均为10.13%),这可能与参试种质大部分为不同时期育成的商业品种有关。变异系数进一步分析显示,不管是新植还是宿根试验,11月的变异系数均大于之后的各月份。相关性分析显示,11月与总平均蔗糖分的表型和遗传相关系数分别为0.94和0.95(P<0.001)。表明11月或更早时间可能更有利于蔗糖分的选择。基于3年蔗糖分数据,发掘出平均蔗糖分超过16.00%的高糖种质32份提供杂交利用,进一步丰富了我国高糖育种亲本基因库。此外,本研究还就进一步促进我国高糖育种研究提出了建议。

High sugar content germplasm is the basic resource for succeeding the breeding of high sugar varieties in sugarcane(Saccharum officinarum L.),and evaluation of its genetic variation is important for improving the breeding efficiency.In this study,the variance and genetic parameters(genetic variance,broad-sense heritability and coefficient of variation and so on)in sucrose content were evaluated using 292 germplasm entries,based on three years(one plant and two ratoon crops)field experiments.The sucrose content among the genotypes were significantly different.The interaction between years and genotypes was not significant,and a high broad-sense heritability(0.85,based on 3-year trial)was found.A considerably broader variation with a mean of 10.66%was observed,while the coefficient of variance(CV)was relatively low with an average of 10.13%.That was possibly caused by the constitution of the germplasm involved in this study as most of the entries were released cultivars.Moreover,we found that CV was highest in the month of November regardless of plant or ratoon crops,and the phenotypic and genetic correlation coefficient reached to 0.94 and 0.95(P<0.001),respectively,implying that selection in November or earlier may be good for sucrose content selection.As a result,32 genotypes with high sugar content(more than 16.00%)were obtained and qualified as high sugar parental germplasm resource for sugarcane breeding.We further proposed some suggestions for high sugar breeding in sugarcane.