豌豆种质资源芽期耐旱性评价及耐旱种质筛选

Evaluation and Screening of Pea(Pisum Sativum) Germplasm Resources for Drought Resistance during Germination Stage

我国是第一大豌豆生产国,在世界豌豆生产中占有举足轻重的地位。然而,干旱是制约我国豌豆生产的主要因素,为了探索豌豆芽期耐旱性,以4份来自不同降雨量地区的豌豆种质为材料,在浓度为0、5%、10%、15%、20%、25%和30%PEG-6000(聚乙二醇)高渗溶液模拟干旱条件产生水分胁迫进行种子萌发试验,试验中测定种子的发芽势、发芽率、发芽指数及简易活力指数4个指标的动态变化,确定了豌豆芽期耐旱性鉴定适宜的PEG-6000浓度为20%~25%。进一步以22%PEG-6000模拟旱胁迫对来自我国18个不同省份的87份豌豆种质资源进行耐旱性鉴定,试验中测定种子相对发芽势、相对发芽率等、萌发耐旱指数及萌发胁迫指数等13个指标,主成分分析确定了相对发芽势、相对发芽率等7项指标作为耐旱综合评价因子,利用隶属函数法,筛选出1份高抗种质(G0002457),来自降水较少的新疆莎车,7份抗旱种质(G0002293、G0005403、G0002418、G0002083、G0000799、G0002017和G0002082),多来自降水较少的西北部春播区。本研究可为耐旱种质的选择提供科学指导,为豌豆耐旱品种改良奠定基础。

China,the largest producer of pea,plays a very important position in world pea production. However,drought is the major restriction factor to the growth of pea. In order to explore the drought resistance of pea accessions,four pea accessions from different precipitation areas were accessed with concentration of 0,5%,10%,15%,20%,25% and 30% of PEG-6000 hypertonic solution simulated drought conditions of water stress for seed germination,to study dynamic change of germination energy,germination rate,germination index and vigor index. The results showed that 20%-25% of PEG-6000 was the suitable concentration range to screen drought resistance resources at germination stage for pea. Drought resistance of 87 pea accessions from 18 different provinces of China were evaluated with 22% PEG-6000 solution. 13 items,including germination energy,germination rate,germination index and simple vigor index,relative germination energy,relative germination rate,relative bud length,relative radical length,relative bud biomass,relative radical biomass,vigor index,germination drought resistant index and germination stress index,were measured in the experiment. Through the analysis of germination indicators,the results showed that germination relevant indicators were significantly inhibited under drought stress with 22% PEG-6000.Compared to the control,the change rate of different indicators average was very different. Simple vigor index was the largest,followed by bud biomass,bud length,germination index,radical biomass and radical length. The coeffi-cient of variation of each germination indicators increased significantly. The order was germination energy,germination rate,germination index,simple vigor index,bud length,bud biomass,radical length and radical biomass. The principal component analysis results showed that relative values of germination energy,germination rate,radical length,radical fresh-biomass,and germination drought resistance index,germination stress index,vigor index were the main impact factors to evaluate drought resistance for pea. Based on the subordinative function analysis of screening results,one genotype（ G0002457） with the highest level（ subordinative function value 0. 80） of drought resistance,seven genotypes with drought resistance（ G0002293 with subordinative function value 0. 61,G0005403,G0002418,G0002083 and G0000799 with the same subordinative function value 0. 65,G0002017 with subordinative function value 0. 67 and G0002082 with subordinative function value 0. 78）,11 moderately resistant genotypes with subordinative function value 0. 40-0. 59,35 susceptible genotypes with subordinative function value 0. 20-0. 39,and 33 highly susceptible genotypes with subordinative function value 0-0. 18,accounted for 1. 15%,8. 05%,12. 64%,40. 23% and 37. 93% of the tested genotypes. Based on analysis of climate data of origin of one genotype with the highest drought-resistance and seven genotypes with drought-resistance,most from spring-growing areas of northwestern China with less precipitation. One genotype with highly resistance from Shache of Xinjiang province with less precipitation. Five of seven genotypes with drought resistance from Ningxia province,one of them from Gansu province and another one from Henan province,which showed the drought resistant of genotypes was related to the orgin of germplasm resources. The eight genotypes with drought-resistance identified were recommended to be used in the drought tolerance improvement for pea breeding.