[目的]阐明壶瓶枣果实发育过程中果柄导管形态及运输效率的变化,明确果实通过维管束系统吸水与其裂果的关系,完善枣裂果机理。[方法]以壶瓶枣(Ziziphus jujube Mill.cv.Huping)为试材,于白熟期(8月19日)开始对选定枣树进行定量灌溉处理,每7 d测定、灌溉一次,使处理组土壤含水量维持在田间最大持水量的(80±5)%,对照组的土壤含水量控制在田间最大持水量的(20±5)%。于果实发育后期分别调查降雨前(9月18日)、降雨后(9月22日)枣果的裂果率;分别在幼果期(7月28日)、白熟期(8月15日)、半红期(9月5日)和全红期(9月17日)进行采样,跟踪枣果实发育进程。品红示踪试验中采用二次枝浸泡和枣吊浸泡两种形式,观察不同时期二次枝、枣吊和果柄维管束系统运输效率的变化;取健康枣果的果柄进行石蜡切片,经FAA液固定、常规方法包埋、制作切片、番红-固绿复染,观察枣果果柄导管形态随果实发育的变化规律。[结果]裂果率调查结果显示,枣果发育后期灌溉和对照两种处理的裂果率分别为2.60%和2.58%,二者间差异不显著,表明充足灌溉并未引起裂果;降雨后,灌溉组和对照组处理的裂果率与降雨前相比均显著升高,分别达到42.90%和40.80%,且两组间差异并不显著,表明降雨会明显导致裂果率上升。品红示踪试验结果表明,在整个果实发育期,品红溶液均能通过二次枝顺畅运送至枣吊,但能否运送至枣果与果实发育期密切相关。幼果期,品红溶液在5 min之内便可顺利输送至枣果,且输送数量和范围随着时间延长而逐渐增大;随着果实发育,品红运输至枣果的难度逐渐增大,白熟期时处理40 min后仅有少许品红输送至枣果;至半红期和全红期,品红溶液几乎不能输送至枣果,这表明果柄可能是品红不能顺利运输至枣果的主要障碍。石蜡切片结果表明,幼果期正常导管所占比例为97.22%,白熟期时正常导管的比例下降至34.95%,且开始出现断裂、退化和畸形,半红期和全红期正常导管的比例仅剩13%左右,导管断裂、退化和畸形进一步加剧,并且开始出现导管堵塞现象,且全红期导管堵塞的数量和程度均高于半红期。[结论]壶瓶枣果实发育后期,果柄导管出现断裂、畸形、退化、堵塞等现象,其运输能力受损或丧失,导致根系吸收的水分难以通过“根系-枝干-二次枝-枣吊-果柄-果实”维管束系统大量进入果实,从而不会引发大量裂果。 [Objective] The purpose was to elucidate the changes of stem morphology and transport efficiency of fruit stem during the fruit development of Kadsura jujube, clarify the relationship between fruit water absorption and its fissure through vascular bundle system, and improve the mechanism of jujube fissure. [Method] With Ziziphus jujube Mill.cv.Huping as test material, the selected jujube trees were dosed at the white ripening stage (August 19), and the jujube was irrigated once every 7 d The soil water content in the treatment group was maintained at (80 ± 5)% of the maximum water holding capacity in the field and that in the control group was controlled at (20 ± 5)% of the maximum water holding capacity in the field. In the late fruit development stage, the fruit cracking rates of jujube were measured before the rain (September 18) and after the rain (September 22) , Half red (September 5) and the whole red (September 17) sampling, tracking Jujube fruit development. In the magenta tracer test, the secondary branch sticking and the jujube hanging immersion were used to observe the changes of transportation efficiency of the secondary branch, jujube and fruiting vascular bundles in different periods. Paraffin sections were obtained from the stems of healthy jujube, The FAA solution was fixed and embedded in the conventional method. The sections were sliced ​​and the saffron-green complex was stained. The changes of the conduit morphology of jujube fruit stalk with the development of the fruit were observed. [Result] The results of split fruit rate showed that the split fruit rate of jujube fruit were 2.60% and 2.58% respectively in the late developmental stage, the difference was insignificant, which indicated that sufficient irrigation did not cause split fruit. After rainfall, Compared with that before rainfall, the rate of cleaved fruit significantly increased to 42.90% and 40.80%, respectively, and the difference between the two groups was not significant, indicating that the rainfall will obviously lead to the increase of cleaved fruit rate. The results of magenta tracing showed that magenta solution could be transported smoothly to jujube by secondary branch during the whole fruit development period. However, the mandarin red jujube fruit could be closely related to the fruit development stage. Young fruit, magenta solution can be successfully transported to the jujube fruit within 5 min, and the number and range of delivery gradually increased with time; with the development of fruit, magenta transported to jujube more difficult , And only a little magenta was delivered to the jujube after 40 min treatment at the white ripening stage. Few mandarin solutions could be delivered to the jujube at the half and mid-red stages, indicating that the stalk may be magenta and could not be transported to The main obstacle jujube. The results of paraffin section showed that the proportion of normal duct in young fruit stage was 97.22%, the normal ductal percentage in white stage decreased to 34.95%, and the percentage of normal duct in fracture, degeneration and deformity, half-red stage and whole-red stage began to appear Only about 13%, catheter rupture, degeneration and deformity further exacerbated, and the phenomenon of ductal congestion began to occur, and the number and extent of catheter blockage during the whole red were higher than half a red period. [Conclusion] The phenomenon of rupture, deformity, degeneration and blockage of the fruiting body catheter occurred during the late development of the fruit of Hupinia scoparia. The transport capacity was impaired or lost, resulting in that it was difficult for the water absorbed by the root system to penetrate into the roots, branches, Jujube hanging - fruit stalk - fruit "vascular system into a large number of fruit, so as not to cause a lot of cracking.