干旱胁迫对不同类型红花品种(系)苗期生理生化特性的影响

摘要

为筛选抗旱品种提供依据,本试验从14份红花品种中筛选出2个抗旱品种(PI401470和PI401477)和2个干旱敏感型品种(系)(PI560169和川红1号),并以此4份品种(系)为材料,研究干旱胁迫对红花幼苗光合、渗透调节物质和抗氧化物保护酶等生理生化特性的影响.结果表明,干旱胁迫下,4个红花品种(系)叶片净光合速率(Pn)、气孔导度(Gs)、胞间CO2浓度(Ci)和蒸腾速率(Tr)均呈不同程度的下降趋势,且品种间差异显著(P﹤0.05);抗旱红花品种(系)的各光合特性指标降幅均低于敏感型红花品种(系).干旱胁迫条件下,渗透调节物质可溶性糖、可溶性蛋白质、脯氨酸含量均上升,保护性酶SOD、POD和CAT活性也均呈升高趋势,且抗旱型红花品种(系)的增长率高于敏感型品种(系);抗旱型品种(系)MDA含量增长率低于敏感型品种.对11项指标进行主成分分析,提取了2个主成分,以净光合速率、气孔导度、胞间CO2浓度、蒸腾速率、SOD活性和CAT活性为第一主成分,以可溶性蛋白质和脯氨酸含量为第二主成分的抗旱性鉴定指标,累计贡献率达89.50％.%To screen the drought-tolerant Carthamus tinctorius L.genotypes growing in Sichuan Province of China,the influences of drought stress on photosynthetic characteristics,contents of osmoregulation substance,pro-tective enzyme activities and the other physiological characteristics of two drought-tolerant and two drought-sensi-tive varieties were studied at safflower seedling stage by drought stress.The results showed that the net photosynthet-ic rate,stomatal conductance,intercellular CO2 concentration and transpiration of 4 safflower varieties declined un-der the drought stress,and the difference among the different varieties was significant(P﹤0.05).The decrease of photosynthetic characteristics of drought-tolerant varieties(lines)was lower than that of the drought-sensitive va-rieties(lines).The contents of permeability regulation substance of leaves such as soluble sugar,soluble protein,prolineand the protective enzyme activities of SOD,POD and CAT were all increased in 4 varieties(lines)under drought stress.Moreover,the increase rate of drought-tolerant varieties was higher than that of drought-sensitive ones.The increase rate of MDA content in drought-tolerant varieties was also lower than that of drought-sensi-tive varieties.Two principal components were obtained by principal component analysis of 11 indexes,and the cu-mulative contribution rate was 89.50％.The net photosynthetic rate,stomatal conductance,intercellular CO2 con-centration,transpiration rate,SOD and CAT activities were used as the primary principal components of drought re-sistance index,while contents of soluble protein and proline were used as the secondary principal component of drought resistance identification index.