节点文献
修剪对葡萄液流和光合同化物运输分配特性的扰动
Pruning Effects on Sap Flow and Transportation Assignment of Photosynthates in Grapevine
【作者】 赵现华;
【导师】 李华;
【作者基本信息】 西北农林科技大学 , 葡萄与葡萄酒学, 2013, 博士
【摘要】 修剪是葡萄栽培管理中必不可少的一项措施,但是修剪等机械伤害会在剪口处形成楔形死组织以及在剪口导管内形成侵填体,影响导管和筛管的运输性能。合理的修剪可以提高葡萄群体与环境的适应性,提高葡萄品质。但是修剪对葡萄生理,尤其是水分和光合同化物的运输分配特性研究不够,本论文以酿酒葡萄为试材对此进行了系统研究,结果如下:1.当薄壁组织细胞的直径小于导管射线间纹孔口的直径时,修剪诱导次生木质部导管腔内侵填体的产生,而且越靠近主干部位的新梢诱导产生的侵填体越多,进程发展越快。在新梢剪口次生木质部约87%导管腔内发现侵填体,其中40%的导管被侵填体完全堵塞。而修剪后1a的多年生部分含有侵填体和被侵填体完全堵塞的导管分别为64%和30%。侵填体在功能性导管中的产生降低了其水分输送性能,最大可降低液流速率21.10%。导管被侵填体部分或完全堵塞后,次生木质部不断分化,产生新的导管,以维持植株的水分输送。2.多年生部分长度与新梢液流成反比,而且液流速率随时间变化明显。受气孔导度下降的影响,各新梢叶片光合速率日变化明显且具有光合“午休”现象。光合速率日变化和浆果糖分卸载量均呈双峰曲线,且次峰值均小于首峰值。随着水分运输距离的延长,各新梢间光合速率和糖分卸载量无显著差异。随着多年生部分的延长,各新梢间光合速率差异不显著,但糖分卸载量显著降低(P<0.05)。修剪后,新梢导管中侵填体的产生与发展要比多年生枝迅速。侵填体发展稳定期新梢木质部中含有侵填体的导管达65%,完全堵塞的导管达到30%,而多年生枝分别为80%和35%。结合以上分析和研究,我们提出了葡萄整形修剪管理的“最小修剪”原则:对葡萄进行整形修剪时,在不妨碍葡萄正常生产的情况下,应该尽量减少剪口数,尽量减少多年生部分,防止多年生部分伸长。3.随着水分运输距离的延长,不同生育期新梢叶片生长速度和生长量均有降低的趋势,各新梢叶片在果实膨大期生长速度和生长量最大。浆果进入转色期前叶片不断生长发育,叶绿素含量稳步增加,在转色期叶片的叶绿素含量最高,而后随叶片的衰老逐渐降低。媚丽葡萄叶片含水量、自由水含量、叶干物质含量以及水分饱和亏缺可塑性小,各新梢上叶片差异不显著。但水势、束缚水含量、束缚水/自由水、叶面积和比叶面积可塑性大,随着水分运输距离的延长逐渐增加且达到显著性差异。新梢比叶重和气孔密度逐渐增大,气孔长度逐渐减小,其中各新梢间叶片气孔密度和气孔长度具有显著性差异,而各新梢叶片厚度和气孔宽度之间无明显差异。葡萄浆果横径生长呈典型的双S曲线,不同新梢浆果横径没有显著差异。随着水分运输距离延长,葡萄浆果糖分卸载量和成熟单粒果实鲜重逐渐下降。但这一趋势在第1和第4,第4和第7新梢上的浆果间并不明显,但第1新梢上的浆果糖分卸载速度明显高于第7个,浆果单粒鲜重达到显著差异水平,而干重之间无显著差异。水分运输距离与枝条成熟度、生长势和木质部宽度成反比,与导管密度和导管长度成正比。第1、第4和第7个新梢木质部导管相对疏导率逐渐增加,分别为3.12、3.40和6.72。导管密度、管腔直径、木质部宽度和导管相对疏导率变化显著。4.研究发现,不同部位新梢液流和浆果糖分卸载成双峰变化趋势,光合速率变化呈“午休”现象,且三者的变化并不同步。随着坐果高度的增加,单干双臂栽培的葡萄各新梢液流速率和浆果糖分卸载普遍低于爬地龙,而光合速率无此变化趋势。随着水分运输距离的增加,单干双臂的葡萄光合速率、液流速率和浆果糖分卸载均逐渐减小。而爬地龙栽培的葡萄由于贴地多年生龙蔓生有大量不定根,各新梢及浆果生长状况基本一致,光合速率、新梢液流和糖分卸载量也一致。5.爬地龙整形方式避免了冬季下架和春季上架,更适合葡萄园机械化操作,与多主蔓扇形和龙干形相比,从葡萄冬季修剪到春季出土单个工人亩劳动时间分别降低了37.50%和27.08%。不同整形方式间葡萄的可溶性固形物、还原糖和滴定酸没有显著差异,而爬地龙方式的稳产性能显著高于其他两种方式。爬地龙整形的葡萄感染炭疽病、白腐病和灰霉病的病穗率高于多主蔓扇形和龙干形,但病果率显著低于后两者。在合理的管理措施下,爬地龙整形方式可以有效控制病虫害的发生,为干旱半干旱埋土防寒区提供了一种合理的整形方式,为实现葡萄优质、稳产、长寿、美观的发展目标奠定了基础。
【Abstract】 In cultivated grapevines, pruning at different locations along the shoot is a normal part ofviticulture, but it may lead to wedge-shaped organization and tylose formation in vessels nearcuts. These physical damages can profoundly affect the transportation capacity of vessel andsieve tube. Reasonable pruning can improve the adaptability of grapevines to environmentand grape quality. However, research of pruning effects on physiological activities of vine isquite few. We have conducted a systematical research on transport and distribution of water,as well as photosynthate during pruning period, using wine grape varieties.1. The results showed that tyloses at the nodes closest to the trunk developed rapidly; andtylose development initiated at the time when the size of vessel-ray pit was longer than that ofparenchyma cell. In current-year shoots, tyloses were formed in up to87%of vessels and40%of the vessels were completely blocked by tyloses. In wound-induced perennial shoots,the percentage was64%and30%, respectively.Tylose formation in functional vessels limited the water transport efficiency (the largestwas21.1%). When vessels were blocked partly or completely by tyloses, new onesdifferentiate to restore the water transport efficiency.2. Perennial cordon length is inversely proportional to sap flow of shoot, so the width ofsap flow is linear to time, that is to say, sap flow has a quick change with time. Induced by thedecrease in stomatal conductance, the diurnal variation of the photosynthetic rate (Pn) wasobvious ‘midday depression of photosynthesis’. The diurnal change of Pn or sugar unloadingis a typical bimodal curve, and the first peak was much higher than that of the second. Therewas no obvious difference among Pn or sugar unloadings of shoots with increasing watertransport distance. With the perennial cordon was longer, there was no obvious differenceamong Pn of different shoots, but the sugar unloadings significantly decreased (P<0.05).After pruning, the emergence and development of tylose in current-year shoot was morerapidly than the perennial cordon. Finally, the partly and completely blocked vessels by tylosein the current-year shoots was65%and30%, respectively, those were80%and35%in theperennial cordon.Based on above analysis and research, we propose a grape pruning management,"minimal pruning principle": when pruning, without influence to the normal production case of grape, the number of cuts and perennial section should be reduced as much as possible toprevent the perennnial section elongation.3. Growth rate and increment of current-year shoot were gradually decreased withincreasing the distance of water transport in development stage. Leaf was continuously grewand developed before veraison stage, chlorophyll content was continuously increasing inleaves of different shoots, while the chlorophyll content was continuously decreasing with theleaf senescence. The contents of total water, free water and dry matter, and the plasticity ofwater saturation deficit of leaf were small, and there was no significant difference amongleaves of different shoots. While, the plasticity of water potential, bound water content,bound/free water, leaf area and specific leaf area was large, and they were continuouslyincreasing with the increase of water transport distance, and even showed statisticallysignificant differences in different treatments. For different shoots, specific leaf weight andstomatal density increased gradually, but stomatal length decreased gradually. The differencebetween stomatal density and stomatal length were significant, but it was not significantbetween leaf thickness and stomtal width.The fruit growth curve of length was ‘double-S’ curve, there was no significantdifference. Sugar unloading and fruit fresh weight were both decreased gradually with theincrease of water transport distance. But the trend of berry in current-year shoot1,4and7was not obvious; the sugar unloading rate of berry in current-year shoot1was significantlylarger than that of current-year shoot7. Results showed significant difference for single fruitfresh weight, but not for the single fruit fry weight.Water transport distance was inversely proportional to shoot maturity, growth vigor andxylem width; and proportional to vessel density and vessel length. The relative grooming rateof vessel was continuously increasing in current-year shoot1,4and7, and the values were3.12,3.40and6.72, respectively. The results showed that vessel density, vessel width, xylemwidth and relative grooming rate of vessel was significantly different.4. The results showed that, the diurnal variation of the photosynthetic rate (Pn) sugarunloading rate is a typical bimodal curve, the diurnal variation of (Pn) demonstrated obvious‘midday depression’, meanwhile, they did not synchronize.With the rise of fruit setting position, sap flow rate and sugar phloem unloading ofdifferent shoots from the Guyot training system were both lower than that of Crawled CordonTraining (CCT), while the Pn has not the trend. With the increase of water transport distance,the Pn, sap flow and sugar phloem unloading of different shoot of the Guyot training systemgradually decreased. The perennial cordon of CCT grew many fibrous roots, and the growthand development of grape berry were uniform in different shoots, the trend of Pn, sap flowand sugar unloading was also uniform when compared with those in grape berries of different shoots.5. CCT shaping method avoided the unmounting in winter and mounting in spring, as aresult it was found easy for mechanized operations. Compared with Multiple main vinefan-training (MVF) and Cordon-training (CT), single worker’s labour time per667.7m2fromwinter pruning to spring unearthing in CCT was decreased37.50%and27.08%, respectively.The contents of soluble solid, reducing sugar and titratable acid in grape of the three shapingmethods had no significant difference. The stable ability of yield in CCT was significantlyhigher than MVF and CT. Moreover, the clusters’ infection rate of grape anthracnose, whiterot and grey mould were higher than those of the other two methods, but the berries’ infectionrate was significantly lower.Under the rational management measures, CCT shaping method can effectively controlpests and diseases, and could be a reasonable viticulture model with the objectives of highquality, stable yield, long-lived and artistic vine production in soil-burying over-winteringzone of arid and semiarid areas.