不同菊花品种根系、地上部和叶片相关指标分析及抗逆性评价

采用盆栽法对6个菊花(Chrysanthemum morifolium Ramat.)品种幼苗的根系和地上部相关指标及叶片光合和气体交换参数进行了比较和相关性分析;并基于叶片相对含水量、相对电导率、丙二醛含量和可溶性糖含量4个生理生化指标,采用隶属函数法对不同菊花品种幼苗的抗旱性和耐热性进行了评价.结果表明:不同菊花品种间幼苗的根系和地上部相关指标及叶片光合和气体交换参数存在一定差异.相关性分析结果表明:根系的大多数相关指标与株高呈显著(P<0.05)或极显著(P<0.01)正相关,但与茎粗和单株叶数却没有显著相关性;并且,单株的根体积、根鲜质量和干质量与单株地上部鲜质量呈极显著正相关(相关系数分别为0.598、0.642和0.599),与单株地上部干质量呈极显著或显著正相关(相关系数分别为0.736、0.606和0.553).主根长与净光合速率和蒸腾速率,平均根长与水分利用效率及单株根鲜质量与蒸腾速率呈显著正相关(相关系数分别为0.475、0.517、0.570和0.477);单株根干质量与蒸腾速率及根系活力与净光合速率和水分利用效率呈极显著正相关(相关系数分别为0.641、0.877和0.814).抗逆性评价结果表明:品种'南农红霞'('Nannong Hongxia')、'大白托桂'('Qx073')和'天使'('Angelina')的平均隶属函数值分别为0.93、0.93和0.72,据此判断这3个菊花品种的抗旱性最强;品种'馒头菊'('Cayman')和'南农红霞'的平均隶属函数值分别为0.82和0.70,据此判断这2个菊花品种的耐热性最强.综上所述,不同菊花品种幼苗的根系相关指标差异明显,并且根系生长状况能够影响地上部的生长和发育,品种'南农红霞'的抗旱性和耐热性均很强,具有较高的抗性育种价值.

Analyses on related indexes of root,above-ground part and leaf of different cultivars of Chrysanthemum morifolium and stress resistance evaluation

Related indexes of root and above-ground part, and leaf photosynthetic and gas exchange parameters of six cultivar seedlings of Chrysanthemum morifolium Ramat. were compared by pot-culture method and their correlation analyses were carried out, and drought resistance and heat tolerance of different cultivar seedlings of C. morifolium were evaluated by subordinate function method according to four physiological and biochemical indexes of leaf including relative water content, relative electrical conductivity, malondialdehyde content and soluble sugar content. The results show that there are some differences in related indexes of root and above-ground part, and leaf photosynthetic and gas exchange parameters of seedlings among different cultivars of C. morifolium. The results of correlation analysis show that there is a significantly ( P<0. 05 ) or extremely significantly ( P<0. 01 ) positive correlation of most related indexes of root with height, but no significant correlation with stem diameter and number of leaves per plant. Besides, there is an extremely significantly positive correlation of volume, fresh and dry weights of root per plant with fresh weight of above-ground part per plant with correlation coefficient of 0. 598, 0. 642 and 0. 599, respectively, and an extremely significantly or significantly positive correlation with dry weight of above-ground part per plant with correlation coefficient of 0. 736, 0. 606 and 0. 553, respectively. There is a significantly positive correlation of main root length with net photosynthetic rate and transpiration rate, of average length of root with water use efficiency, and of fresh weight of root per plant with transpiration rate with correlation coefficient of 0. 475, 0. 517, 0. 570 and 0. 477, respectively, and there is an extremely significantly positive correlation of dry weight of root per plant with transpiration rate, and of root activity with net photosynthetic rate and water use efficiency with correlation coefficient of 0. 641, 0. 877 and 0. 814, respectively. The results of stress resistance evaluation show that average subordinate function values of cultivar 'Nannong Hongxia ' , 'Qx073 ' and 'Angelina ' are 0. 93, 0. 93 and 0. 72, respectively, therefore, drought resistance of the three cultivars of C. morifolium is the strongest. While those of cultivar 'Cayman ' and 'Nannong Hongxia ' are 0. 82 and 0. 70, respectively, therefore, heat tolerance of the two cultivars of C. morifolium is the strongest. In conclusion, the differences in related indexes of root of different cultivar seedlings of C. morifolium are obvious, and root growth status can affect growth and development of above-ground part. Both drought resistance and heat tolerance of cultivar 'Nannong Hongxia' are very strong, so it has a higher value in breeding resistance.