滇重楼种质资源抗旱综合评价及生理机制研究

水分是限制滇重楼种子休眠萌发及资源分布的重要成因。以云南滇重楼主产区6个种源地的种子为试验材料，湿度设置分别为10%（正常水分处理，CK）和3%（水分胁迫处理，T），测定10、30和60 d时种子的可溶性蛋白（soluble protein，SP）、丙二醛(malondialdehyde，MDA)、过氧化氢酶(catalase，CAT)、过氧化物酶(peroxidase，POD)和超氧化物歧化酶(superoxide dismutase，SOD)的生理活性，对资源进行综合抗旱评价,并筛选抗旱生理指标。结果表明：随胁迫时间延长，滇重楼种子可溶性蛋白呈先下降后回升的趋势，而SOD和CAT酶活性呈先升高后降低的趋势，MDA和POD呈下降趋势。CAT活性对水分胁迫最为敏感，胁迫和对照间呈显著差异，60 d时呈极显著差异（P＜0.01）；在10 d时SOD和MDA对水分胁迫呈极显著响应（P＜0.01），在30 d时各生理指标均受到显著影响，SOD和POD受到极显著影响（P＜0.01）。相关性分析结果显示，可溶性蛋白与SOD和POD呈显著负相关（P＜005）。滇重楼种质资源之间变异系数较大，不同种质材料对干旱胁迫的敏感性不同。综合分析，师宗、鹤庆和石林的滇重楼种源抗旱性较强，耿马地区抗旱性最弱，可为进一步抗旱基因型品种选育提供理论依据。不同评价方法对滇重楼抗旱生理指标筛选的结果较为一致，CAT、SOD和MDA可作为抗旱性鉴定的生理指标。

Comprehensive Evaluation and Physiological Mechanism of Drought Resistance of Paris polyphylla Smith var. yunnanensis (Franch.) Hand.-Mazz Germplasm Resources

Moisture is an important cause of limiting the seed dormancy germination and resource distribution of P. polyphylla Smith var. yunnanensis (Franch.) Hand.-Mazz. This paper took the seeds from 6 provenances areas of Yunnan province as test materials, set up moisture content 10% (normal treatment, CK) and 3% (water stress treatment, T), and measured the physiological activities of soluble protein(SP), malondialdehyde(MDA), catalase(CAT), peroxidase (POD) and superoxide dismutase(SOD) in seeds at 10,30 and 60 d after treatments, then evaluated comprehensively the drought resistance of resources and screened the physiological indexes of drought resistance. The results showed that: with the prolongation of stress time, the SP decreased first and then recovered, while the activitives of SOD and CAT increased first and then decreased, and MDA and POD showed a decreasing trend. CAT activity was the most sensitive to water stress, and there was a significant difference between water stress treatment and CK at 60 d (P<0.01). 10 d after water stress treatment, SOD and MDA showed a significant response to water stress (P<0.01). All indexes were significantly affected at 30 d, especially SOD and POD (P<0.01). There was a significant negative correlation between SP and SOD, POD (P<0.05). The variation coefficient among the germplasm resources of P. polyphylla Smith var. yunnanensis (Franch.) Hand.-Mazz was large and the sensitivity of different germplasm materials to drought stress was different. The comprehensive analysis showed that the Shizong, Heqing and Shilin had stronger drought resistance, while that of Gengma was the weakest, which could provide theoretical basis for further drought-resistant genotype selection of varieties. The results of screening the physiological indexes of drought resistancewere consistent in different methods, and CAT, SOD and MDA could be used as physiological indexes for drought resistance identification.