水杨酸和甜菜碱浸种对低温干旱胁迫下玉米芽苗期生长的影响
低温和干旱是春玉米萌发阶段的主要威胁。研究沙培条件下不同浓度水杨酸和甜菜碱浸种后对胁迫下玉米萌发和解除胁迫后苗期生长性状的影响并比较不同胁迫类型间的药剂浸种效果差异。结果表明：与低温胁迫相比,低温干旱双胁迫使玉米发芽势、地上部干鲜重和鲜重根冠比极显著下降。水杨酸和甜菜碱均能显著提高不同胁迫下玉米籽粒发芽势,显著减少可溶性糖含量。对于幼苗高度和幼苗干鲜重,药剂浸种表现为低温胁迫下抑制效果和低温干旱双胁迫下促进作用。根系总长对药剂浸种的响应强于其他根系性状,且对甜菜碱的响应更为显著,地上部生长对水杨酸的响应强于甜菜碱。随着药剂浓度升高,水杨酸效果减弱,甜菜碱效果增强。两种药剂浸种效果表现最佳的分别是SAC1和GBC3。
英文摘要:
Chill and drought are the main stresses to spring maize (Zea mays L.) during the germination stage. An experiment was conducted in order to investigate the effect of presoaking with salicylic acid and betaine on germination under chill and drought stress and following seedling growth without stress of maize through sand culture method, the presoaking effects with salicylic acid and betaine between two stress types were also compared. The main results showed that germinability, fresh and dry weight of shoot, root/shoot ratio of fresh weight significantly decreased under chill and drought stress when compared with that under chill stress. Salicylic acid and betaine significantly improved germinability and reducing soluble sugar content under both two stress types. Contrary effects of presoaking on height and fresh and dry weight of seedling occurred between single chill stress and chill with drought stress, inhibitive effect and promotion effect was manifested under two stress types respectively. The response of total root length to presoaking was stronger than that of other root characteristics, and this response was more significant in betaine treatments than in salicylic acid treatments, to which that shoot growth showed better response. With the increase of chemicals concentration, the effect of salicylic acid decreased, and on the contrary, the effect of betaine enhanced. The best performance of two chemicals were SAC1 and GBC3, respectively.
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