青稞种质资源成株期抗旱性鉴定及抗旱指标筛选

Drought resistance identification and drought resistance indexes screening of Tibetan hulless barley resources at adult stage

干旱是影响青藏高原青稞生产的主要因素之一,鉴定青稞种质资源成株期抗旱性,筛选可靠的抗旱指标,可对抗旱青稞品种培育提供依据。本研究以238份青稞种质为材料,于2019和2020年在甘肃省张掖市设置正常灌水和干旱胁迫2个处理,测定青稞株高、单株穗数、单株生物量、单穗粒重、穗长、千粒重和产量,结果表明:采用抗旱性度量值(D值)、综合抗旱系数(CDC值)、加权抗旱系数(WDC值)分别进行成株期抗旱性综合评价。相关性分析表明,干旱胁迫对各指标的影响均达到极显著水平,产量与株高、千粒重呈极显著正相关,与单穗粒重呈显著正相关。频次分析表明,各指标对干旱胁迫的敏感程度依次为株高、产量、单株生物量、单穗粒重、单株穗数、穗长和千粒重。基于D值、CDC值及WDC值的种质排序基本一致。灰色关联度分析表明,各指标DC值与D值之间的关联度大小依次为产量、单株生物量、单穗粒重、株高、单株穗数、穗长和千粒重,这与各指标DC值与WDC值的密切程度基本一致。逐步回归分析表明,产量、株高、单株穗数、千粒重及单株生物量可作为青稞成株期抗旱鉴定的可靠指标,D值为适宜的抗旱评价方法。以D值为依据将供试青稞种质划分为5个抗旱等级,筛选出紫眼窝青稞、六棱青稞、紫青稞、ZDM8125、土葫芦紫青稞等1级抗旱种质38份。研究结果为青稞抗旱品种选育和抗旱机制研究提供了重要基础材料和理论参考。

Drought is one of the main factors affecting the production of hulless barley in the Qinghai-Tibet Plateau. Identification of drought resistance of hulless barley germplasm resources at adult stage and screening of reliable drought resistance indexes can provide basis for breeding drought resistant varieties. In the present study, a total of 238 hulless barley germplasms were used as materials, and two treatments of normal irrigation and drought stress in the field conditions were conducted in Zhangye of Gansu Province in 2019 and 2020, respectively. Seven indexes, such as the plant height, spike number per plant, biomass per plant, grain weight per spike, spike length, 1000-grain weight, and yield were determined. The drought resistance comprehensive evaluation value(D-value), comprehensive drought resistance coefficient(CDC-value), and weight drought resistance coefficient(WDC-value) were used to identify drought resistance at adult stage of hulless barley germplasms. The results showed that the effects of drought stress on all indexes were extremely significant, and the correlation analysis showed that the yield was significantly positively correlated with plant height and 1000-grain weight at P < 0.01, and significantly positively correlated with nificantly positively correlated with plant height and 1000-grain weight at P < 0.01, and significantly positively correlated with the grain weight per panicle at P<0.05. Frequency analysis showed that the sensitivity of seven indexes to drought stress was plant height, yield, biomass per plant, grain weight per ear, number of ears per plant, ear length and 1000-grain weight, respectively.The ranks of drought resistance of germplasms based on the D-value, CDC-value, and WDC-value were similar. Grey correlation degree analysis showed that the correlation degree between DC-value and D-value was in the order of yield, biomass per plant,grain weight per spike, plant height, number of spikelets per plant, ear length and 1000-grain weight, which was basically consistent with the close degree between DC-value and WDC-value of each index. Stepwise regression analysis showed that yield, plant height, panicle number per plant, 1000-grain weight and biomass per plant could be used as reliable indexes for drought resistance identification of hulless barley in adult stage. D-value was determined as the appropriate method for drought resistance identification. Based on D-value, the tested hulless barley germplasms were divided into five drought resistance grades, and 38 germplasms were classified in grade I, such as Ziyanwoqingke, Liulengqingke, Ziqingke, ZDM8125, Tuhuluqingke, etc. These results provided important basic materials and theoretical reference for the breeding of drought-resistant varieties and the study of drought-resistant mechanism of hulless barley.