川西北高原50份燕麦种质农艺性状遗传多样性分析及综合评价

Genetic diversity analysis and multivariate evaluation of agronomic traits of 50 oat germplasm lines in northwest Sichuan

为客观评价燕麦种质资源农艺性状的遗传多样性,本试验对50份国外引进燕麦种质资源的27个农艺性状进行了形态多样性指数分析,并对其中的16个数量性状进行相关性分析、聚类分析和主成分分析,结果表明:遗传多样性指数最高的是穗长(H′=2.04),变异系数最大的是营养枝数(63.36%);鲜草产量与干草产量、株高、分蘖数等呈极显著正相关(P<0.01);聚类分析将50份燕麦种质资源分为4大类群,第Ⅰ类群为早熟种质,具有植株高大、单株鲜草产量高、茎节数和小穗多、茎秆粗壮等特点,可作为选育多目标性状的优良种质或材料;第Ⅱ类群为中晚熟种质,但有益性状不明显;第Ⅲ类群属于中熟种质,植株分蘖能力强,种子千粒重高,可作为选育高产分蘖能力强的优良亲本;第Ⅳ类群属于晚熟种质,植株茎秆粗壮,可作为选育抗倒品种的优良亲本。主成分分析将16个数量性状指标集中在累计贡献率达77.00%的5个主成分中:第一主成分与燕麦牧草产量密切相关;第二主成分载荷最高的是单株营养枝数;第三主成分载荷最高的是生殖枝数;第四和五主成分主要反映茎节数和株高。综上所述,川西北地区引进的50份国内外燕麦种质资源的遗传多样性丰富,综合评价表明,种质Golden Yellow、Lightning、Golden RainⅡ、BambullⅡ可以作为亲本以改良当地燕麦品种。

This research aimed to objectively evaluate the genetic diversity of agronomic traits in 50 oat germplasm accessions.Twenty seven agronomic traits were evaluated;a morphological diversity index was calculated for each of them;and correlation,cluster and principal component analyses were performed for 16 selected quantitative traits among them.It was found that the trait with the highest genetic diversity index was panicle length(H′=2.04),and the highest coefficient of variation(63.36%)was for vegetative tiller number.The yield of fresh grass,hay yield,plant height,tiller number,and a number of other traits showed a very significant positive correlation(P<0.01).Cluster analysis divided the 50 oat germplasm accessions into four major groups.GroupⅠwas characterized by high grass yield and plant height,a greater number of internodes and spikelets,and sturdy stems.This group was considered to provide excellent parent material for breeding projects involving multiple target traits.GroupⅡcomprised mid-late maturing germplasm,without obvious beneficial traits.GroupⅢcomprised medium-value germplasm,with potential for breeding high for yield and tillering ability.GroupⅣincluded late flowering germplasm,with heavier stems,which would provide excellent parent material for breeding lodging resistant varieties.The principal component analysis reduced the 16 analyzed traits to 4 principal components which cumulatively explained 69.00%of the data variation.The first principal component was closely related to forage yield;for the second principal component,the highest loading coefficient was for vegetative tillers per plant.For the third principal component accessions were primarily differentiated on the number of reproductive branches.The fourth principal component mainly reflected the number of stem nodes.Tin summary,the 50 evaluated oat germplasm accessions introduced from northwestern Sichuan and from abroad,have wide genetic diversity.Multivariate evaluation of measured traits indicated that accessions‘Golden Yellow’,‘Lightning’,‘Golden RainⅡ’,and‘BambullⅡ’can be used as parents to improve local oat varieties.