灵武长枣根蘖苗与嫁接苗叶片光合特性的比较

Comparison of photosynthetic characteristics between the root tiller seedlings and grafted seedlings of Ziziphus jujube‘Lingwuchangzao’

【目的】比较灵武长枣根蘖苗与嫁接苗叶片在光合特性方面的差异,以期为栽培和选育高光效、高品质、高产量的灵武长枣提供科学支撑及理论依据。【方法】以根蘖和嫁接两种方式繁殖的灵武长枣植株为试验材料,比较两者在叶面积、叶片营养元素含量、叶绿素相对含量、蒸腾速率、气孔导度、胞间二氧化碳浓度、净光合速率、水分利用率、叶绿素荧光参数等方面的差异。【结果】在整个生长期,灵武长枣嫁接苗叶面积始终大于根蘖苗,叶面积的增长幅度略有不同,但总体趋势基本一致;叶片营养元素含量在整个生长期内不断变化,N含量持续下降,根蘖植株P含量在7月中旬达到峰值(6.82 g/kg),随后下降,至9月下旬又略有增加,嫁接苗不断下降,根蘖和嫁接苗的K含量呈现先升高后下降的趋势,均在8月10日达到最大值,分别是23.92和23.58 g/kg,总体来看,灵武长枣嫁接苗叶片N和P元素高于根蘖苗,但K元素积累量低于根蘖苗;在整个生长期内,灵武长枣根蘖苗叶绿素SPAD值显著高于嫁接苗,8月中旬达到峰值,根蘖苗比嫁接苗高了12.88%;灵武长枣根蘖苗在观测期内的光合作用各指标均大于嫁接苗,其中蒸腾速率、气孔导度、净光合速率均存在显著性差异;叶绿素荧光参数结果显示,灵武长枣根蘖苗初始荧光小于嫁接苗,其他各参数均高于嫁接苗,且PSⅡ最大光能转化率Fv/Fm、PSⅡ潜在光化学效率、光下最大荧光Fm’和PSⅡ实际光化学效率Y(Ⅱ)具有显著性差异。【结论】灵武长枣根蘖苗较嫁接苗光能利用率更高,光合作用更强,具有更大的高产潜能,可作为下一步选育高光效、高产量、高品质灵武长枣品种试验的重点材料。

【Objective】The objective of this study was to compare the differences in photosynthetic characteristics between root tiller seedlings and grafted seedlings of Ziziphus jujube‘Lingwuchangzao’,to provide a theoretical basis and scientific support for the cultivation and selection of Lingwuchangzao with a high light efficiency,high quality and high yield.【Method】In this study,the differences in leaf area,leaf nutrient content,relative chlorophyll content,transpiration rate,stomatal conductance,intercellular carbon dioxide concentration,net photosynthetic rate,water use efficiency,chlorophyll fluorescence parameters and so on were compared between root tiller seedlings and grafted seedlings of Lingwuchangzao.The results showed that the leaf area of the grafted seedlings was always larger than that of root tiller seedlings throughout the growth period,and the growth rate of leaf area was slightly different,but the overall trend was the same.The leaf nutrient content changed continuously throughout the growth period,the N content continued to decrease,and the P content of the root tiller seedlings reached the peak value of 6.82 g/kg in mid-July,which then decreased and subsequently increased slightly in late September.The P content of the grafted seedlings decreased continuously.The K content of both root tiller seedlings and grafted seedlings showed a trend of first increasing and then decreasing,both reaching the maximum values of 23.92 g/kg and 23.58 g/kg on August 10.In general,the contents of N and P in the grafted seedlings of Lingwuchangzao were higher than those in the root tiller seedlings,while the accumulation of K elements in the grafted seedlings was lower than that of the root tiller seedlings.In the whole growth period,the chlorophyll SPAD value of the root tiller seedlings was significantly higher than that of the grafted seedlings,reaching the peak value in mid-August,which was 12.88%higher than that of the grafted seedlings.The chlorophyll fluorescence parameters showed that the initial fluorescence of the root tiller seedlings of Lingwuchangzao was 12.35%lower than that of the grafted seedlings,while all the other parameters were higher than those of the grafted seedlings,among which the maximum light energy conversion rate Fv/Fm,potential light energy conversion rate of PSⅡ,the maximum fluorescence under light Fm’and the actual photochemical efficiency Y(Ⅱ)of PSⅡshowed significant differences.【Conclusion】The results of this study showed that the root tiller seedlings of Lingwuchangzao have higher light energy utilization and photosynthesis as well as greater high-yielding potential than the grafted seedlings,which can be used as the next key material for the selection and breeding of high-light efficiency,high-yielding and high-quality varieties of Lingwuchangzao.