摘心对基质栽培蓝莓生长及花芽形成的影响

Effects of pinching on growth and flower bud formation of substrate cultivated blueberry

【目的】基质栽培蓝莓存在营养生长过旺、花芽形成少的问题,严重影响着树体丰产。研究新梢摘心对基质栽培蓝莓树体生长及花芽形成的影响情况,为蓝莓基质栽培管理提供科学依据。【方法】以3年生基质盆栽蓝莓品种‘利珀蒂’为试材,分别于2021年6月5日(Z1)、6月15日(Z2)、6月25日(Z3)这3个日期进行新梢长度保留为20~30 cm的摘心处理,同时进行新梢长度分别保留为25~30(A1)、20~25(A2)、15~20(A3)、10~15 cm(A4)的4个不同程度的摘心处理,以不修剪的为对照(CK),并分别测定树体的营养生长、生殖生长、叶片光合特性和生理指标,分析不同日期和不同程度的摘心处理对基质栽培蓝莓生长及花芽形成的影响情况。【结果】不同日期和不同程度的摘心处理后,Z2与A2处理的株高、冠幅、新梢长度均值均显著低于CK的,而其成枝数最多;其结果枝数量与花芽形成数量均显著高于CK和其他相同水平处理的,其结果枝数量分别为29.33和31.67个,比CK分别提高了37.5%和65.6%,其平均单株花芽形成量分别为88.33和93.33个;Z2与A2处理的单株产量均值分别为777.30和821.30 g,比CK分别提高了48.5%和75.0%。与CK相比,不同日期与不同程度的摘心处理均提高了叶片的净光合速率(Pn)、气孔导度(Gs)、蒸腾速率(Tr)和叶绿素(Chl)含量,降低了胞间二氧化碳浓度(Ci),其中,Z2与A2处理的提高幅度分别最高;不同程度摘心处理后的30~120 d内,各个摘心处理的叶片中可溶性蛋白的含量均呈现出先升后降的变化趋势。不同日期的摘心处理中,Z2处理的叶片中可溶性蛋白含量的平均值比CK的提高了21.1%,而Z1与Z3处理的均下降;不同程度的摘心处理中,A2处理的叶片中可溶性蛋白的含量相对较高,而其C/N值却呈先降后升的变化趋势,Z2与A2处理的C/N值均显著高于CK和相同处理组中其他处理的,摘心处理提高了ABA/IAA、ABA/GA3、ZR/IAA、ZR/GA3之值,其中Z2与A2处理的提升幅度分别最大。【结论】摘心修剪有效抑制了树体的营养生长,促进了其生殖生长,提高了叶片中可溶性蛋白的含量,显著提高了叶片的Pn值、Chl含量和C/N值,对于调节内源激素的平衡、促进树体花芽的分化、提高花芽的形成量和单株产量均有重要作用;在实际生产管理中,可以于6月中旬采取新梢长度保留为20~25 cm的摘心修剪方式,这样可以促进基质栽培蓝莓的生长,使其形成大量的花芽。

【Objective】Excessive vegetative growth and less flower bud formation in the substrate-cultivated blueberry seriously affects the yield of the tree.The effect of new shoot pinching on the growth of blueberry tree and flower bud formation were studied,which can provide scientific basis for the substrate-cultivated blueberry management.【Method】The three-years-old matrix potted blueberry cultivar‘Liberty’was used as the experimental material.On June 5(Z1),June 15(Z2)and June 25(Z3),pinching was performed respectively with 20-30 cm of new shoots preserved,and at the same time,four different degrees of pinching treatments,i.e.,25-30 cm of new shoots(A1),20-25 cm(A2),15-20 cm(A3)and 10-15 cm(A4),with no pruning as the control,were used to measure the vegetative growth,reproductive growth,leaf photosynthetic characteristics and physiological indicators of the tree to explore the effect of pinching on the growth and flower bud formation of substrate-cultivated blueberry.【Result】The plant height,crown width and average length of shoots of Z2 and A2 treatments were significantly lower than those of CK after different dates and different degrees of pinching,and the amounts of branches was the largest;the amounts of bearing shoots and flower buds in the tree were significantly lower compared with CK and other treatments at the same level,the amounts of bearing shoots were 29.33 and 31.67,which were 37.5%and 65.6%higher than CK.The average amounts of flower buds per plant was 88.33 and 93.33,respectively;the average yield per plant was 777.30 g and 821.30 g,which were 48.5%and 75.0%higher than those of CK.Compared with CK,the net photosynthetic rate(Pn),stomatal conductance(Gs),transpiration rate(Tr)and chlorophyll(Chl)content of leaves were increased and the intercellular carbon dioxide concentration(Ci)was decreased under different dates and different degrees of pinching.Among them,the growth rate of Z2 and A2 pinching treatment was the highest;within 30~120 days after treatment,the content of soluble protein in leaves tended to decrease following the initial increase.The average content of soluble protein in the leaves of Z2 treatment was 21.1%higher than that of CK,while that of Z1 and Z3 treatment decreased in different dates of pinching treatment;in different degrees of pinching,the leaves soluble protein content of A2 treatment was relatively high,while its C/N value showed a trend of decreasing first and then increasing.The C/N values of Z2 and A2 treatments were significantly higher than those of CK and other treatments at the same level.Pinching treatment increased ABA/IAA,ABA/GA3,ZR/IAA and ZR/GA3 ratio,with Z2 and A2 processing the largest improvement.【Conclusion】Pinching can effectively inhibit the vegetative growth of the tree,promote the reproductive growth,increase the content of soluble protein in the leaves,and significantly increase the Pn,Chl and C/N of the leaves.It plays an important role in the differentiation of body flower buds,increasing the amount of flower bud formation and the yield per plant;in the actual production management,we can adopt the method of pinching in mid-June to keep the new shoots 20~25 cm to promote the growth of matrix-cultured blueberries and form a large number of flower buds.