不同山核桃品种(系)嫁接幼苗生长及光合特性的比较

Comparison of growth and photosynthetic characteristics fluorescence parameters of different Carya cathayensis cultivars(line)

【目的】为山核桃良种育苗提供技术参考。【方法】以5个山核桃品种(系)嫁接苗为研究对象,2021年12月采集山核桃穗条,于2022年4月嫁接,同年7月使用光合测定分析仪测定嫁接苗的光合参数,使用叶绿素荧光仪测定叶绿素荧光特性,比较不同品种(系)间叶片光合特性、叶绿素荧光特性及生长指标,并进行了光合参数、叶绿素荧光参数及生长指标的相关分析。【结果】5个山核桃品种(系)的净光合速率(P_(n))、胞间CO_(2)浓度(C_(i))、蒸腾速率(T_(r))、水分利用率(EW)、光化学猝灭系数(PQ)、非光化学猝灭系数(NPQ)、最大光合效率(F_(v)/F_(m))、成活率、苗高及叶片数量等指标均存在极显著差异。P_(n)与Tr、实际光合效率(Y_(Ⅱ))极显著正相关,与C_(i)、气孔导度(G_(s))、F_(v)/F_(m)显著正相关,与NPQ显著负相关;G_(s)与NPQ显著负相关;苗高与地径、叶片数量极显著正相关。根据隶属函数值,5个山核桃品种(系)嫁接苗的生长状况由优到劣排序依次为‘沙河’‘宁国山核桃2号’‘宁国山核桃5号’‘宁国山核桃4号’‘宁国山核桃3号’。【结论】5个山核桃品种(系)嫁接幼苗的生长状况存在差异。‘沙河’‘宁国山核桃2号’嫁接幼苗生长状况较优,蒸腾速率较高,水分利用率低,在育苗时应保证充足的光照及水分供应。‘宁国山核桃2号’‘宁国山核桃5号’耗散过剩光能的能力最强,具有较强的光保护能力;对于其他山核桃品种(系)嫁接苗,苗期建议搭建遮阳网进行适度遮阴。

【Objective】To provide a theoretical basis for seedling breeding of Carya cathayensis.【Method】Five grafted C.cathayensis cultivars(lines)were used as materials.The scions were collected in December 2021,which were grafted in April 2022.The photosynthetic characteristics of different cultivars of C.cathayensisin,including net photosynthetic rate(P_(n)),intercellular CO_(2)concentration(C_(i)),stomatal conductance(G_(s))and transpiration rate(T_(r))were measured by photosynthesis system in July.The chlorophyll fluorescence parameters,including actual photosynthetic efficiency of actual photosynthetic efficiency(Y_(II)),photochemical quenching coefficient(PQ),the maximum photochemical efficiency(F_(v)/F_(m))and non-photochemical quenching coefficient(NPQ)were measured.The photosynthetic parameters and chlorophyll fluorescence parameters was analyzed,and the photosynthetic capacity of 5 C.cathayensis,cultivars was evaluated by membership function method.【Result】There were significant differences in net photosynthetic rate(P_(n)),photochemical quenching coefficient(PQ),the maximum photochemical efficiency(F_(v)/F_(m)),stomatal conductance(G_(s)),transpiration rate(T_(r))and water use efficiency(WUE).The results of correlation analysis showed that net photosynthetic rate was significant positively correlated with net photosynthetic rate(P_(n))and transpiration rate(T_(r)),Y_(II),was positively correlated with C_(i),G_(s)and F_(v)/F_(m),and was negatively correlated with NPQ.The seedling height was positively correlated with the diameter and the number of leaves.Using membership function method,the photosynthetic capacity of 5 cultivars of C.cathayensis were in the order of was Shahe>Ningguo No.2>Ningguo No.5>Ningguo No.4>Ningguo No.3.【Conclusion】There were significant differences in photosynthetic characteristics among 5 C.cathayensis,Ningguo No.2 and Ningguo No.5 had higher photosynthetic capacity,higher transpiration rate and lower water use efficiency,Ningguo No.2 and Ningguo No.5 had the best ability to dissipate excess light energy and heat,and had higher ability of light protection.It is suggested that other varieties should be covered by shading net in moderate level.