甘蔗亲本与家系宿根黄化评价

Ratoon chlorosis evaluation of sugarcane parents and families

【目的】分析甘蔗宿根黄化遗传特点与亲本耐宿根黄化差异,为开展甘蔗耐宿根黄化育种及相关研究提供参考。【方法】以383个甘蔗亲本和97个甘蔗家系为试验材料,开展5个宿根作物季的田间宿根黄化试验,并进行性状相关分析、方差分析、遗传力和育种值计算及聚类分析。【结果】甘蔗宿根黄化高峰期出现4月下旬至5月上旬,黄化程度随生长期延长而下降,随宿根年限延长而加重,并受试验地影响。相关分析结果显示,宿根黄化影响甘蔗农艺性状,且发生较重时易与农艺性状呈显著负相关(P<0.05)。遗传力计算结果表明宿根黄化属低至中等偏低遗传力性状,亲本试验的广义遗传力为0.22~0.45,家系试验的广义遗传力为0.22,狭义遗传力为0.25。方差分析结果显示,宿根黄化受到亲本、时期、试验地、年度、作物季等多种因素的影响,主要效应中仅亲本显著存在,另外4个因素将通过互作影响甘蔗宿根黄化,其中影响最重要的是试验地×时期、亲本×试验地等互作,亲本位居第五。亲本或家系间宿根黄化差异最大时期为宿根发苗中后期而不是宿根黄化率最高时期。表型预测值聚类分析结果表明,超过63.6%亲本和64.9%家系的耐宿根黄化能力属较好以上;育种值聚类分析结果表明,仅30.3%亲本属耐宿根黄化能力较好以上,不及亲本表型值分类的一半,亲本育种值评价结果与表型值评价结果存在差异。【结论】甘蔗宿根黄化属低至中等偏低遗传力性状,影响因素众多,并以互作影响为主。易受试验地微小环境和田间管理影响,将给甘蔗宿根黄化田间试验研究与耐宿根黄化新品种选育带来不利影响。

【Objective】In order to understand the genetic characteristics of sugarcane ratoon chlorosis and ratoon chlorosis resistance difference among parents,and to provide reference for ratoon-chlorosis-resistant sugarcane breeding and relevant research.【Method】With 383 sugarcane parents and 97 sugarcane families as experimental materials,ratoon chlorosis field trials in 5 ratoon crop seasons were carried out,and trait correlation analysis,analysis of variance,calculation of heritability and breeding values and cluster analysis were performed.【Result】The peak of ratoon chlorosis was from late April to early May. The degree of chlorosis decreased as sugarcane grew,increased as ratoon grew,and was affected by the experimental field. Correlation analysis showed that ratoon chlorosis would affect sugarcane agronomic traits,and it had significant negative correlation with agronomic traits when it was severe(P<0.05). The result of heritability calculation showed that ratoon chlorosis was a trait of low to intermediate heritability,with a broad-sense heritability of 0.22-0.45 for parent tests and 0.22 for family test,and a narrow-sense heritability of 0.25 for family test. Analysis of variance showed that ratoon chlorosis was affected by many factors,including parents,time,experimental field,year and crop season,among which only parent was significant,and the other 4 factors affected sugarcane ratoon chlorosis through interaction,among which the most important were experimental field×time,parent×experimental field,and the effect of parents ranked the 5th. The period of maximum difference of ratoon chlorosis between parents or families was the middle-later stage of ratoon seedling period rather than the stage when ratoon chlorosis incidence rate was the highest. By phenotypic BLUP,cluster analysis showed that more than 63.6% of parents and 64.9% of families had better ratoon chlorosis resistance. By breeding value,only 30.3% of the parents had better ratoon chlorosis resistance,less than half of its phenotypic value classification result. Differences existed between evaluation results of parental breeding value and phenotypic value.【Conclusion】Sugarcane ratoon chlorosis is a trait of low to intermediate heritability,which is affected by many factors,mainly interaction. This trait is easily affected by the micro environment and field management,which will have an adverse impact on the field experimental research on sugarcane ratoon chlorosis and breeding of new ratoon-chlorosis-resistant varieties.