野生二棱大麦种子休眠型态与农艺性状及生态地理因素相关性研究

对来自以色列不同地区16个生态型野生二棱大麦种子的休眠型态与其农艺性状及起源地生态地里因素的相关性进行了研究。结果表明：高温（40℃）储藏可以打破种子的休眠;16个生态型种子在高温处理下的萌发率表现出显著差异,其休眠打破过程显示出不同型态的对数生长曲线：8个旱生生态型为S型,而8个湿生生态型为倒L型。休眠深度用实际达到最大萌发率的时间度量,最低休眠深度（15·6d）是来自湿润地区＂进化峡谷＂的生态型37-N,而最深休眠深度（103·1d）是来自干旱地区Ein-Zukim（死海附近）的生态型32-6。此外,对11个物候及农艺性状指标与休眠深度做斯皮尔曼秩相关分析,结果有9个显示出显著相关,尤其是粒重与休眠深度有极显著相关性。同时,休眠深度与起源地15个生态地理因素中的9个有显著相关,种子休眠主要受其起源地的地理位置、温度和水分条件等影响。可见,野生二棱大麦自然选择进化了休眠特性去应对干热环境而繁衍生息。本研究结果可用于进一步遗传研究和现代栽培大麦品种的改良。

Caryopsis Dormancy Patterns of Wild Barley(Hordeum spontaneum)and Its Association with Agronomic Traits and Ecogeographical Parameters

Patterns in caryopsis dormancy and its agronomic and ecogeographical associations were investigated in 16 wild barley (Hordeum spontaneum) ecotypes from different habitats in Israel.The results showed that heat treatment (40℃) could break dormancy of caryopses.Germination percentages under breaking dormancy treatments were significantly different among the 16 ecotypes.Dormancy-break patterns were fitted by logistic growth curves: all eight xeric ecotypes showed an S-shaped curve,whereas all eight mesic ecotypes displayed a reverse L-shaped curve.For depth of dormancy,as reflected by the time to maximum germination percentage,the lowest (15.6 days) was for the ecotype 37-N from the north slop of Evolution Canyon (mesic),whereas it was the highest (103.1 days) for 32-6 from Ein-Zukim (near Dead Sea) (xeric).In addition,nine of 11 Spearman' s Rho Correlations between dormancy depth and agronomic traits of 16 H.spontaneum ecotypes were significant.Dormancy depth showed closest correlation with kernel weight.Nine of 15 correlations between dormancy depth and ecogeographical factors were significant.Caryopses dormancy was mainly influenced by their original location,as well as temperature and local water conditions.Therefore,natural selection adapted wild barley to a dry and warm environment by increasing dormancy. The results of dormancy in wild barley will be subjected to genetic analyses and should be helpful for improving modern barley cultivars.