外源物质浸种对迟播油菜越冬期抗寒性及产量的影响

Effects of seed soaking with exogenous substances on late-seeded rapeseed cold resistance of during overwintering period and yield

确保迟播油菜产量是压减长江流域双季稻区冬闲田的关键,提高越冬期抗寒性、促进冬前干物质积累是增加迟播油菜产量的有效途径。播前外源物质浸种是提高越冬期抗寒性,促进冬前快速生长的有效措施。试验选用早熟品种华油杂137,设置清水(CK),0.01 mmol L-1、0.05 mmol L^(-1)、0.10 mmol L^(-1)的甜菜碱(T1-1、T1-2、T1-3),0.1 mmol L^(-1)、0.5 mmol L^(-1)、1.0 mmol L^(-1)的脯氨酸(T2-1、T2-2、T2-3),0.03%、0.15%、0.30%的过氧化氢(T3-1、T3-2、T3-3),0.001 mmol L^(-1)、0.01 mmol L^(-1)、0.05 mmol L^(-1)的苹果酸(T4-1、T4-2、T4-3),25 mg L^(-1)、100 mg L^(-1)、300 mg L^(-1)的氧化纳米锌(T5-1、T5-2、T5-3),0.5 mmol L^(-1)、1.0 mmol L^(-1)的多胺(T6-1、T6-2)浸种处理后,于2021—2023年开展田间试验,研究不同外源物质及浓度浸种对迟播油菜越冬期抗寒性及产量的影响。结果表明,不同外源物质和不同浓度浸种处理影响迟播油菜出苗率,部分处理如T3-3、T4-2、T5-3与CK相比显著提高,提高幅度分别达到19.2%、15.3%、17.3%。部分外源物质浸种也显著提高了迟播油菜抗寒性,其机制一方面是提高抗氧化系统中过氧化物酶、过氧化氢酶活性和谷胱甘肽含量,减少活性氧、过氧化氢及丙二醛含量,另一方面是增加可溶性糖、脯氨酸、苹果酸、多胺、甘露醇等渗透调节物质含量,提高膜联冷应答蛋白激酶含量从而提高抗寒性。叶片抗寒性的增加有利于越冬期叶片生物量的积累,有效分枝数增加,单株角果数增加,从而促进产量的提高。另外,对筛选出的9个正向指标和3个负向抗寒性指标进行综合评价,结果表明,2年平均产量排序和抗寒性综合评价值排序结果基本一致,产量较高、抗寒性较强的浸种处理为T5-3、T5-2、T2-3、T1-2。该研究可为长江流域迟播油菜冬前壮苗培育、提高越冬期抗寒性提供理论与技术支撑,为迟播油菜抗逆稳产、促进冬闲田开发利用提供依据。

In double-cropping rice areas in the Yangtze River Basin(YRB),ensuring the yield of late-seeded rapeseed is essential to reduce the winter fallow fields.Additionally,promoting the accumulation of dry matter before winter and improving cold resistance during the overwintering period are effective ways to increase the yield of late-seeded rapeseed.Soaking seeds with exogenous substances is an effective measure to improve the cold resistance during the overwintering period and promote the rapid growth before winter.In this experiment,the early maturing rapeseed variety Huayouza 137 was selected,while soaking-seed treatments of water(CK);0.01 mmol L^(-1),0.05 mmol L^(-1),0.10 mmol L^(-1) betaine(T1-1,T1-2,T1-3);0.1 mmol L^(-1),0.5 mmol L^(-1),1.0 mmol L^(-1) proline(T2-1,T2-2,T2-3);0.03%,0.15%,0.30%hydrogen peroxide(T3-1,T3-2,T3-3);0.001 mmol L^(-1),0.01 mmol L^(-1),0.05 mmol L^(-1) malic acid(T4-1,T4-2,T4-3);25 mg L^(-1),100 mg L^(-1),300 mg L^(-1) nano zinc oxide(T5-1,T5-2,T5-3);0.5 mmol L^(-1),1.0 mmol L^(-1) polyamines(T6-1,T6-2)were conducted between 2021 and 2023 rapeseed growing season.We studied the effects of soaking seeds with different exogenous substances and their levels on the cold resistance in winter and yield of late-seeded rapeseed.The results showed that the different exogenous substances and their levels of soaking seeds affected the germination rate of late-seeded rapeseed,and part of them,such as T3-3,T4-2,and T5-3,significantly increased by 19.2%,15.3%,and 17.3%versus CK.Soaking seeds with some exogenous substances significantly improved the cold resistance of late-seeded rapeseed in winter.On the one hand,the activities of peroxidase,catalase,and the content of glutathione were improved,and the contents of hydrogen peroxide,active oxygen and MDA reduced;on the other hand,the contents of soluble sugar,proline,malic acid,polyamine,and mannitol were increased;at the same time,the content of membrane cold response protein kinase was increased.The increase of leaf cold resistance was beneficial to the accumulation of leaf biomass and the increase of effective branches and pod number per plant,thus promoting yield.In addition,9 positive and 3 negative cold resistance indicators were comprehensively evaluated.The results showed that the two-year average yield ranking and the comprehensive evaluation value ranking of cold resistance were basically the same over the two years.While the soaking-seed treatments with the best yield and cold resistance were T5-3,T5-2,T2-3,and T1-2.These results of this study provide theoretical and technical support for the cultivation of late-seeded rapeseed seedlings before winter and the improvement of cold resistance in the YRB,and provide a basis for the stress resistance and stable production of late-seeded rapeseed and the development and utilization of winter fallow fields.