玉米萌发期是齐苗壮苗的关键，本试验利用育苗钵称重精确控制土壤水分方法设置35%和75%土壤相对含水量（RWC）在人工气候室内对河南省推广的十个玉米品种进行萌发期抗旱性综合评定。通过系统分析播种一周后干旱胁迫对玉米发芽、根系生长、干物质转化等12个指标的影响，表明干旱胁迫降低了玉米的发芽势、发芽率、发芽指数和种子萌发抗旱指数，降低了地上部分与地下根的长度与干物质量，增大了根冠比，降低了贮藏物质转运率。利用主成分分析与热图分析聚类，筛选得出玉米萌芽期抗旱鉴定的四级指标分别为：干物质积累量、发芽指数和种子萌发抗旱指数是评价萌芽期抗旱性的一级指标；根长、根冠比和根干重等根系特征作为二级指标；根体积和贮藏物质转运率为三级指标；发芽势作为评价的四级指标。此外将所有指标按照对抗旱性影响的差异分为四大类，分别为第一类：发芽率、发芽指数、种子萌发抗旱指数；第二类：根体积、贮藏物质转运率；第三类为根冠比，第四类：根长和芽长。对10个栽培种萌芽期抗旱性按照综合值进行评价，其抗旱性强弱先后为：XD29、LY35、WG704、JX1、XY335、BY989、ZD958、WK702、NY2、DH605。
英文摘要:
Maize seed germination stage is vital for its subsequent growth and yield. In order to investigate the effect of drought stress on maize germination, seeding pot experiment has been conducted with 35% and 75% relative soil water content to evaluate the drought tolerance of 10 popularity varieties of Henan province in germination period. The results showed that seed germination potential, germination rate and germination index, aboveground and belowground biomass, plant height and root length after seedling has been significantly decreased. Drought stress increased the root/shoot ratio and storage substance remobilization rate. Combination of principal component analysis (PCA) and heat map analysis showed that four level indexes had been established. The first principal component was related to dry matter, germination index and germination drought resistance index, the second principal component was mainly related to root properties including root length, root-shoot ratio and dry root weight, the third principal component including root volume and the storage substance remobilization rate, and the forth principal component was germinating potential. In addition, all indexes were divided into four categories according to the response of drought on seedling emergence. Seed germination related index was included in the first class, root volume and the storage substance remobilization rate were the second class, the third class was root-shoot ratio, and root length and plant height were the forth class. PCA and heat map clustering analysis showed that drought tolerance of 10 varieties was in the order of XD29, LY35, WG704, JX1, XY335, BY989, ZD958, WK702, NY2, DH605.
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