油菜3个栽培种发芽期耐盐性评价

Evaluation for Salt Tolerance of Three Cultivated Species of Rapeseeds at Germination Stage

对油菜种质资源进行耐盐性评价是培育耐盐油菜品种的基础性工作。本研究在室内分别采用3种盐(NaCl)浓度(86 mmol/L、170 mmol/L、256 mmol/L)对芥菜型油菜(Brassica juncea)、白菜型油菜(B.rapa)和甘蓝型油菜(B.napus)等3个栽培种的203份种质资源进行盐胁迫,结果表明盐胁迫对各栽培种的发芽率有不同程度抑制作用,白菜型油菜表现最好,甘蓝型油菜次之,芥菜型油菜最差。基于发芽率筛选出14份优异种质。进一步利用梯度浓度盐(NaCl)溶液对其进行胁迫,发现各栽培种发芽率均随着盐浓度的升高呈下降趋势,符合Boltzmann曲线,但白菜型油菜下降最为缓慢。通过比较盐胁迫下各栽培种6个性状值(胚轴长、根长、总鲜重、地上部分鲜重、总叶绿素含量和电导率)后发现,白菜型油菜发芽期耐盐性优于甘蓝型油菜和芥菜型油菜。对170 mmol/L NaCl胁迫下14份种质各性状值的主成分分析表明,白菜型油菜Br2、甘蓝型油菜Bn1和Bn3为最耐盐种质,可用于耐盐油菜品种的培育。

Evaluation of the salt tolerance on existed rapeseeds germplasms is the primary work for breeding salt-tolerance varieties. 203 accessions of three cultivated species including Brassica juncea, B. rapa, and B. napus were stressed by three NaCl concentrations （86 mmol/L, 170 mmol/L, and 256 mmol/L）and the germination rate （GR）was checked. The results showed that the GRs of three species were all inhibited but with different degrees under salt stress and B. rapa performed best,which followed by B. napus and B. juncea sequentially. Fourteen lines with good GRs were then stressed by gradient NaCl concentrations and results indicated that the GRs of three species decreased as the Boltzmann curve with the increasing NaCl concentrations,and B. rapa did most slowly all the time. Six physiological characters including hypocotyl length, root length, plantlet fresh weight, up-ground fresh weight, total chlorophyll content, and electrical conductivity of the fourteen lines under the stress of three NaCl concentrations mentioned above were detected. It approved that the general salt tolerance of B. rapa was better than B. juncea and B. napus. The principle component analysis（PCA） of the trait values under 170 mmol/L NaCl stress revealed that Br2 of B. rapa and Bnl and Bn3 of B. napus were the best salt-tolerant germplasms which could be used in the future breeding application.