通过表型和基因型鉴定筛选适合春油菜区的优异种质

Identification and screening of elite germplasm for spring rapeseed area by genotyping and phenotyping

为了更好地利用甘蓝型油菜资源,以引进的124份和青海省20份甘蓝型油菜资源为材料,利用50K SNP芯片分析了这些资源的遗传多样性,并在春油菜环境下鉴定了开花期、茎秆强度、产量和品质等13个相关性状。结果表明:资源两两之间的遗传距离平均为0.4683,遗传距离大于等于0.5的资源对数占总对数的36.45%,表明这批资源的遗传多样性丰富。所有资源按地理来源划分为6个类群,西北春油菜资源群内遗传差异相对较小,但与国内其它4个类群间存在较大的遗传差异,平均遗传距离均超过了0.4。聚类分析表明,地理来源难以再作为遗传差异的有效判断依据。鉴定出具有茎直径超过17 mm、主茎木质部厚度超过1 mm、茎折断力超过80 N、茎秆强度超过40 N/cm^(2)、千粒重超过6 g、含油量超过48%等单一优良性状的资源若干份,可用于春油菜种质创新和品种改良。筛选出22份综合性状优良的资源,构成两个杂交优势群,一个为西北和国外资源群,另一个为长江流域资源群,两个群之间具有较大的遗传差异。

In order to make full use of the introduced rapeseed germplasm,genetic diversity of 144 rapeseed(Brassica napus L.)resources(including 124 exotic lines and 20 local spring rapeseed lines in Qinghai Province)was analyzed using 50K SNP microarray.In addition,13 important phenotypic traits,including flowering time,stem strength-related traits,yield-related traits and quality traits,were identified in spring rapeseed planting environment.Results showed that mean value of genetic distances among 144 germplasm resources was 0.4683.36.45%germplasm resources had genetic distance greater than or equal to 0.5.It indicated that the genetic diversity of these resources was relatively rich.144 resources were divided into 6 groups according to their geographical origin.Among them,the group of spring rapeseed resources from northwest China had great genetic differences with other groups.Although had less diversity than other groups,it still had more than 0.4 inside.Cluster results showed that geographical origin of materials could not be really valid for judging their genetic differences.Some elite resources were identified with at least one excellent traits including large stem diameter(greater than 17 mm),thick xylem(≥1 mm),strong stem(breaking strength≥80 N,or stem strength≥40 N/cm^(2)),large TSW(thousand seed weight≥6 g),high oil content(≥48%).Among them,22 germplasm with excellent comprehensive traits were found and could be constructed into 2 hybrid parent resource groups.One group was from northwest China and abroad,the other is from the Yangtze River Valley in China.