甘蔗亲本田间自然抗病性评价及广义遗传力分析

Evaluation and broad sense heritability analysis of disease resistance of sugarcane parents under field conditions

【目的】了解甘蔗亲本对甘蔗病害的抗性及病害发生的特点、影响因素和性状遗传力,为开展甘蔗抗病育种提供参考依据。【方法】选用463个甘蔗亲本在广西农业科学院甘蔗研究所丁当试验基地(以下简称丁当点)、广西百色市农业科学研究所试验基地(以下简称百色点)和四川省农业特色植物研究院资中试验基地(以下简称资中点),实施两轮田间自然抗病性评价,并进行方差分析、广义遗传力计算和聚类分析。【结果】在丁当点、百色点和资中点分别发现甘蔗病害18、17和15种。除花叶病和黑穗病外,发病相对较重的还有褐条病、赤腐病、轮斑病、黄点病和叶枯病,其病情指数均大于10.00。方差分析结果表明,不同病害的显著性影响因素不同,且多数病害的互作方差占比高于主效应方差占比。试验点内联合分析时,丁当点内亲本方差显著(P<0.05,下同)或极显著(P<0.01,下同)的病害为轮斑病、赤腐病、黄点病、锈病、褐斑病、梢腐病和紫斑病,百色点内亲本方差显著或极显著的病害为轮斑病、黄点病、赤腐病、梢腐病和叶焦病,资中点内亲本方差显著的病害为赤条病;所有试验点联合分析时,亲本方差显著或极显著的病害为轮斑病、黄点病、赤腐病、叶焦病和紫斑病。广义遗传力计算结果表明,甘蔗白叶病属中等遗传力性状,白疹病、锈病、轮斑病、褐条病和叶焦病属中等偏低遗传力性状,叶枯病、赤腐病、梢腐病、紫斑病、赤条病、黄点病、褐斑病和虎斑病属低等遗传力性状,但进行联合方差分析时仅轮斑病、黄点病、赤腐病、叶焦病和紫斑病存在广义遗传力,可通过多年多点田间试验进行抗病选择。不同选育年代甘蔗亲本的抗病性未呈现持续向好的选择结果,仅褐条病和叶枯病存在波动;不同来源甘蔗亲本的赤腐病、轮斑病、眼点病和叶枯病存在显著或极显著差异,其中,桂糖和粤糖亲本的抗病性较差,台糖亲本的抗病性较好,Ho亲本对轮斑病的抗性较好,对赤腐病的抗性较差,CP亲本对轮斑病和叶枯病的抗性较好,对赤腐病的抗性较差。在测试亲本中,抗病性好、较好和一般的亲本分别占3.02%、26.57%和49.03%,抗病性较差和差的亲本分别占18.57%和2.81%。在抗病性好和较好的亲本中,育种利用效果好的不足10.00%;许多利用效果好的亲本抗病性中等,加上抗病表现较差或差亲本的大量使用,致使甘蔗抗病育种水平提升受到影响。【结论】抗轮斑病、黄点病、赤腐病、叶焦病和紫斑病甘蔗亲本可通过多年多点田间试验选择,感白条病、白叶病、白疹病、赤条病、褐斑病、褐条病、虎斑病、梢腐病、锈病、眼点病和叶枯病甘蔗亲本材料宜淘汰;合理选用甘蔗抗病亲本和改进病害抗性评价方法有利于提高甘蔗抗病育种水平。

【Objective】To understand the disease resistance of sugarcane parents,and the characteristics of disease occurrence,influencing factors,heritability of traits,and provide reference for disease resistance breeding in sugarcane.【Method】Two rounds of field disease resist⁃ance trial,including 463 sugarcane parents,were carried out in Dingdang Experimental Base of Sugarcane Research Institute,Guangxi Acade⁃my of Agricultural Sciences(hereinafter referred to as Dingdang),Experimental Base of Baise Agricultural Research Institute,Guangxi(here⁃inafter referred to as Baise)and Zizhong Experimental Base of Sichuan Institute of Agricultural Special Plants(hereinafter referred to as Zizhong),and analysis of variance,broad sense heritability calculation and cluster analysis were processed.【Result】There were 18,17 and 15 sugarcane diseases were found in Dingdang,Baise and Zizhong,respectively.Except for mosaic and smut disease,the relatively severe dis⁃eases were brown stripe,red rot,ring spot,yellow spot and leaf blight disease,with a disease index greater than 10.00.The result of analysis of variance showed that the significant influence factors of different diseases were different,and the proportion of interaction variance of most diseases was higher than that of main effect variance.In the joint analysis of variance within the experimental location,the disease with signif⁃icant(P<0.05,the same as below)or extremely significant(P<0.01,the same as below)parental variance in Dingdang were ring spot,red rot,yellow spot,rust,brown spot,pokkah boeng and purple spot disease,in Baise were ring spot,yellow spot,red rot,pokkah boeng and leaf blight disease,in Zizhong was red stripe disease.The diseases with significant or extremely significant parental variance in all experimen⁃tal locations were ring spot,yellow spot,red rot,leaf scorch and purple spot disease.The calculation of broad sense heritability showed that sugarcane white leaf disease was a medium heritability trait,white rash,rust,leaf spot,brown streak and leaf scorch disease were medium low heritability traits and leaf blight,red rot,pokkah boeng,purple spot,red streak,yellow spot,brown spot and banded sclerotial disease were low heritability traits.However,only ring spot,yellow spot,red rot,leaf scorch and purple spot disease had broad sense heritability in the joint a⁃nalysis of variance,which could be selected through multi⁃year multi⁃location field trials.Parents from different breeding ages did not show sustained positive selection results,only brown stripe and leaf blight disease showed fluctuation;Parents from different sources had significant or extremely significant differences in the resistance to red rot,ring spot,eye spot and leaf blight disease,among them,the resistance of Guitang parents and Yuetang parents was poor,while the resistance of Taitang parents was good.The resistance of Ho parents to ring spot dis⁃ease was good,while the resistance to red rot disease was poor;The CP parents had good resistance to ring spot and leaf blight disease,but poor resistance to red rot disease.Among the tested parents,3.02%had better disease resistance,26.57%had good disease resistance,49.03%had moderate disease resistance,18.57%had poor disease resistance,and 2.81%had poorer disease resistance.Among parents with good and better disease resistance,less than 10.00%had good utilization performance in sugarcane breeding;Many parents with good utilization performance just had moderate disease resistance,even parents with poor or poorer disease resistance were widely used,affecting the improvement of sugarcane disease resistance breeding.【Conclusion】Sugarcane parents for disease resistance of ring spot,yellow spot,red rot,leaf scorch and purple spot disease could be selected through multi⁃year multi⁃location of field trials.Sugarcane parents susceptible to leaf scald,white leaf,white rash disease,red stripe,brown spot,brown stripe,banded sclerotial,pokkah boeng,rust,eye spot and leaf blight disease should be eliminated.Reasonable selection of sugarcane disease resistant parents and improvement of disease resistance evaluation methods are conducive to promote the improvement of sugarcane disease resistance breeding.