甘蓝型油菜抗裂角材料资源的筛选

Screening of Germplasm with Resistance to Pod Shattering in Rapeseed(Brassica napus L.)

抗裂角性是油菜机械化品种选育中的重要性状,筛选抗裂资源材料对于开展抗裂育种具有重要意义。本文应用随机碰撞法和田间落粒法,对不同来源的75份甘蓝型油菜资源进行了抗裂角性鉴定。结果表明,抗裂角性在参试材料内存在较大的遗传变异。抗裂角指数（SRI）的范围为0.01-0.70,变异系数为70.70%。田间落粒率的范围为1.58%-55.51%,变异系数为62.53%。相关分析表明,SRI值与田间落粒率相关性不明显。对于易裂和抗裂材料,2种评价方法之间的差异小,而对于抗裂性中等的材料,2种评价方法之间差异大;田间落粒率、SRI与角果皮厚度的相关系数分别为-0.429和0.687,均达显著水平。因此,角果皮厚度可作为田间筛选抗裂资源的辅助指标;利用2种方法筛选出1份抗裂性强材料Ny。Ny具有角果皮厚,果皮表面光滑的特点。在极端落粒情况下（黄熟后2周）Ny的落粒率为7.74%,正常落粒情况下（黄熟后1周）落粒率为1.58%,其抗裂角指数（SRI）值2011年和2013年分别为0.70和0.48,高于其他材料。

Shattering resistance is an important trait for rapeseed varieties suitable for mechanical harvesting, therefore screening of germplasm with pod shattering resistance is the basic work for the breeding of shattering resistance. In the present paper, we employed two methods, including random impact test （RIT） and shattering percentage test in the field, to evaluate pod shattering resistance of 75 accessions of B. napus. These accessions displayed wide variation in shattering resistance index （SRI） and shat-tering percentage （SP） in the field, which ranged from 0.01 to 0.70 with the variance coefficient （CV） of 70.70% for SRI, and from 1.58% to 55.51% with CV of 62.53% for SP in the field. The simple correlation analysis showed there was no correlation between pod SRI and SP in the field when all accessions included. However, for the accessions with strong or weak shattering resistance, there was no difference between two methods, except for the accessions with the shattering resistance between strong and weak ones. The SP and the wall thickness of pod had significantly negative correlation （r = -0.429）, pod SRI and the wall thickness of pod had significantly positive correlation （r = 0.687）. Thus, the pod wall thickness can be used as an auxiliary index to screen shatter resistant germplasm. A germplasm Ny with high pod shattering resistance was identified in this study. Ny has thicker wall and smoother surface of pod. The shattering percentage of Ny was 7.74% under adverse condition （two weeks after the maturity）, and 1.58% under normal condition （one week after maturity）. The pod SRI of Ny was 0.70 in 2011 and 0.48 in 2013, higher than those of rest materials. Ny will be a valuable resource for rapeseed breeding for pod shattering resistance in the future.