干旱胁迫对大豆生长的影响及抗旱性评价方法与指标筛选

Effects of Drought Stress on Growth and Screening Methods and Indexes for Drought-Resistance in Soybean

2014-2015年在年降雨量不足40 mm的敦煌市,设干旱和正常灌水两个处理,通过测定12份大豆品种的8个形态指标(株高、主茎节数、有效分枝数、单株荚数、单株粒数、单株粒重、单株生物量和百粒重)及小区产量,采用改进抗旱指数法及权重隶属函数值D对其进行抗旱性评价,并筛选出3份不同抗旱类型的大豆品种进行生理指标测定,验证该方法和指标。结果显示,与灌水处理(CK)相比较,干旱胁迫下的8个形态指标及产量,2014年除有效分枝数及百粒重差异不显著外,其余考察性状均达到了极显著差异,2015年所有考察表型性状均达到极显著差异;两年权重隶属函数法评价结果显著相关,小区产量与两年两种评价方法极显著相关;两种处理下,中度抗旱(中黄24)、弱抗旱品种(WDD00172)的SOD活性、POD活性、CAT活性、丙二醛含量、可溶性糖含量差异极显著,且与权重隶属函数值D显著相关,而强抗旱品种(晋豆21号)中SOD活性、POD活性、脯氨酸含量差异不显著,且6个生理指标与权重隶属函数值D均不相关。因此,权重隶属函数法和小区产量可作为大豆抗旱性评价单一可靠的方法与指标。

Twelve representative soybean varieties were used for the evaluation of drought resistance under two given treatments （drought stress and normal irrigation）in Dunhuang City （Gansu Province）with an annual rainfull below 40 mm in 2014 and 2015. Two evaluation methods, an improved drought index evaluation and a weight subordinate function evaluation （D value）were applied to evaluate drought-resistance using eight morphological traits （plant height, number of main stem nodes, branch number, pod number per plant, seed number per plant, yield per plant, biomass per plant and 100-seed weight）and plot yield. Three different type of drought-resistant soybean varieties were detected for six physiological indexes of SOD （superoxide dismutase） , POD （peroxide） , CAT （cat- alase） activities, MDA （malondialdehyde） content, Pro （ proline ） content and SS （ soluble sugar） content to vali- date the evaluation methods and the suitability of the physiological indexes as indicators of drought resistance. The results showed that six morphological traits and plot yield, except branch number per plant and 100-seed weight in 2014 ,and all the traits in 2015 reached significant differences in drought stress treatment against the irrigation treatment （CK）. The weight subordinate function evaluation highly coincided,with a significant correlation among varieties and plot yield showed an extremely significant correlation with the index values of the two evaluation methods between the two years. Six physiological indexes showed that under two treatments conditions, the three different drought-resistant type varieties had larger differences in these indexes among varieties, and also week drought-resistant WDD00172 and moderate drought-resistant Zhonghuang No. 24 had extremely significant differences between the both treatments of drought stress and normal irrigation in all the physiological indexes, whereas high drought-resistant Jindou No. 21 did not, which suggested that although the activities or contents of the six physiological indexes were significantly correlated with the weight subordinate function evaluation of week and moderate drought-resistant varieties, they were not correlated with the weight subordinate function evaluation of high drought-resistant varieties. Therefore, the results obtained in this work strongly suggest that the weight subordinate function evaluation can be used as an effective method and plot yield as a reliable index in drought resistance evaluation.