生草栽培对南方鲜食枣生长及光合特性的影响

【目的】筛选适宜南方鲜食枣园生草栽培的草种。【方法】以白三叶、多年生黑麦草、1年生黑麦草为试材,采用Li-6400XT便携式光合仪测定枣树的光合指标,研究不同生草栽培处理对鲜食枣的生长及光合作用的影响。【结果】3个草种生草栽培处理均可促进鲜食枣的生长,其中白三叶生草栽培处理中鲜食枣的株高增幅、地径增幅、枣吊长度、SPAD值分别比对照高出30.94%、9.83%、11.58%、26.39%,优于其他处理。不同生草栽培处理中,鲜食枣的光合能力差异显著,其中白三叶生草栽培处理的最大光合速率为16.83 μmol/(m^2·s),显著高于其他处理,而光补偿点和暗呼吸速率分别为11.62、3.36 μmol/(m^2·s),显著低于其他处理。鲜食枣的净光合速率日变化呈双峰曲线,峰值分别出现在11:00和17:00,白三叶生草栽培处理11:00的净光合速率最高,为18.79 μmol/(m^2·s)。蒸腾速率和气孔导度的日变化趋势与净光合速率一致,而胞间CO_2浓度呈早晚高、中午低的不规则"V"形曲线变化,在13:00降到最低值,之后又逐渐回升。按照净光合速率、蒸腾速率和气孔导度的日变化均值由高到低排序,依次均为白三叶生草栽培处理、多年生黑麦草生草栽培处理、1年生黑麦草生草栽培处理、对照。【结论】综合各处理对鲜食枣主要生长指标和光合指标的影响,白三叶生草栽培处理下,鲜食枣可充分利用光合有效辐射和CO_2,提高净光合速率,进而促进树体生长。

Effects of sod culture on growth and photosynthetic characteristics of fresh edible jujube in southern China

【Objective】To screen out some species suitable for sod culture in fresh edible jujube of southern China.【Method】Using Trifolium repens,Lolium perenne and L.ultiflorum as test materials,some photosynthetic indexes were determined by using Li-6400XT portable photosynthetic apparatus,and effects of different sod culture treatments on growth and photosynthesis of fresh edible jujube were researched.【Result】Three grass sod culture treatments all can promote growth of fresh edible jujube.In T.repens sod culture treatment,plant height increment,ground diameter increment,bearing branch length,and SPAD value are 30.94%,9.83%,11.58%,26.39%higher than control,and better than those of other treatments.Meanwhile,photosynthetic capacities of fresh edible jujube have significantly difference among three sod culture treatments.The maximum photosynthetic rate is 16.83μmol/(m2·s)in T.repens sod culture treatment,which is significantly higher than that of other treatments.However,light compensation point and dark respiration rate are 11.62 and 3.36μmol/(m2·s)in T.repens sod culture treatment,which are significantly lower than those of other treatments.Diurnal variation of net photosynthetic rate of fresh edible jujube show a double-peak curve,and peak values occur at 11:00 and 17:00,respectively.Net photosynthetic rate in T.repens sod culture treatment is the highest at 11:00,up to 18.79μmol/(m2·s).Diurnal variation trends of transpiration rate and stomatal conductance are consistent with net photosynthetic rate.Intercellular CO2 concentration occurs higher values in the morning and evening,and the lowest value at 13:00,showing an“V”shape curve.Based on average daily variation values of net photosynthetic rate,transpiration rate and stomatal conductance from high to low,the orders are the same as T.repens sod culture treatment,L.perenne sod culture treatment,L.ultiflorum sod culture treatment,control.【Conclusion】Based on effects of each treatment on main growth indexes and photosynthetic indexes of fresh edible jujube,in T.repens sod culture treatment,fresh edible jujube can make full use of photosynthetically active radiation and CO2 to increase net photosynthetic rate and promote tree growth.