【作者】 江国良；

【导师】 张光伦；

【作者基本信息】 四川农业大学 ， 果树学， 2011， 博士

【摘要】 本研究采用田间生物学、生态学调查观测,栽培试验与室内生理生化分析相结合的综合研究方法,首次在27°-34°N、102°-104°E的四川枇杷主栽地理区域内,选取了亚热带湿热少日照、亚热带半干热多日照和南温带半干暖多日照三大差异性生态型区,对不同生态型区枇杷的生长、结果、产量和品质形成的生态作用、效应及指标,枇杷的花期调控技术,大棚栽培的生理生态,花果冻害的生理生态及防治挽救措施等进行了较深入研究。1.在亚热带湿热少日照生态型区,枇杷以夏梢成花为主,花期在9-12月,果实集中成熟期在5月,品质中上。易发生低温冻害、日灼、裂果、缩果、叶斑病、花腐病等。在亚热带半干热多日照生态型区,枇杷春、夏梢均易成花,花期在6-11月,无冻害发生,果实没有生长停滞期,成熟早,成熟期10月-翌年4月,但第一批花结的果实小、品质差。易发生枝干腐烂病、芽枯病和果实栓皮病。在南温带半干暖多日照生态型区海拔较低的河谷地带,枇杷的生态反应与在亚热带湿热少日照生态型区接近,但物候期晚20-30d,以夏梢成花为主,果实品质特优。随着海拔的上升,枇杷年生长量逐渐减少,春梢成为主要结果母枝,成花量减少,冻害频率和程度增加。海拔达到1920m时,由于夏秋季温度低,枇杷成花极少,冻害特重,不适宜进行经济栽培。2.在亚热带半干热多日照生态型区,开花期调控是枇杷取得经济产量的关键,短截能显著推迟开花期和果实成熟期,最佳短截时间是2月中旬-4月上旬。短截配合肥水控制是最有效的调节开花期的途径,能显著减少早花和晚花的数量,果实集中成熟期被调节到12月-翌年3月。通过不同生态型区组合、不同熟期品种搭配和综合运用花期调控技术,可以基本实现四川枇杷鲜果周年应市。3.在亚热带湿热少日照生态型区,枇杷简易大棚内气温高于露地气温,且棚内土壤温度随大气温度升高而升高,但土壤温度变化幅度较小。棚内地面覆盖塑料薄膜能提高土壤温度,不同薄膜类型间的温度差异较小。大棚内空气相对湿度高于露地。大棚内土壤湿度相对稳定,棚内地面覆膜比未覆膜和露地的土壤湿度高。露地栽培的光照效果最好。大棚内地面覆膜处理中,银色反光膜处理的光反射能力最强。大棚内枇杷的末花期比露枇杷提早5-6d,果实成熟期提早10d,春梢抽发时间提早7d,夏梢抽发时间提早3-4d。大棚果实外观为长椭圆形,露地果实外观近圆形；大棚枇杷果实体积和可滴定酸含量大于露地枇杷,果实的可溶性固形物、可溶性总糖含量均低于露地枇杷。大棚内采用地面覆膜处理可以提高果实的可溶性固形物、可溶性糖含量,对果实体积影响不明显。大棚栽培增加了果实日灼病和缩果病的发病率,降低了果实锈病和裂果率。4.在亚热带湿热少日照生态型区和南温带半干暖多日照生态型区,利用褐变法研究冻害指数发现,平坝稻田枇杷比丘陵区枇杷受冻重,幼果比不同发育时期的花容易受冻,刚开放的花和未开放的花蕾抗冻能力最强。塑料大棚比树冠覆膜、树冠覆盖遮阳网和果实套袋等的防冻效果好。在90%以上相对湿度、温度在-0.6--1.1℃下持续3小时的霜冻就会导致花及幼果不同程度的冻害,低温、高湿时间越长,霜冻越强,冻害程度越重。通过生理指标分析,发现SOD活性和相对电导率与坡地枇杷冻害指数间线性相关性突出,达极显著水平。MDA含量与抗寒性呈负相关,但枇杷冻害指数与MDA含量线性相关性不显著；游离脯氨酸含量随着温度降低而增加。坡地枇杷花果相对电导率与冻害指数间相关性达极显著水平。5.喷施水杨酸(SA)和二氯化钙(CaCl2)可显著提高枇杷抗冻性,其最佳浓度分别是90mg/L和2g/L。枇杷各组织抗冻生理指标对低温及外源物质反应不一致,相同生理指标在枇杷不同组织的活性或含量差异较大；外源物质对叶片叶绿素含量影响不显著；喷施水杨酸,花中脯氨酸含量极高。MDA指标显示水杨酸处理效果优于二氯化钙和二氯化钙加硫酸钾处理。冻害发生后用赤霉素200mg·kg-1+吡效隆(CPPU)20mg·kg-1处理果肉未褐变的受冻幼果可刺激幼果继续发育成为有商品价值的果实,激素处理增大果型指数,减少种子数量,能挽回一定经济损失,可作为冻害发生后的应急处理技术。本研究结果,初步揭示了枇杷在四川三大典型生态型区的主要生物学特性和生态适宜性；探讨了亚热带半干热多日照生态型区枇杷成花特性、成花条件与枇杷生境的关系,揭示了枇杷—年多次开花结果的原因；研究提出的开花期调控技术途径,突破了传统方法调控开花期的局限性,根本解决了枇杷夏季早花多、秋季花量不足的问题；明确了简易大棚对棚内生态因子及枇杷生长发育、开花结果、产量品质的影响；探索了枇杷冻害发生规律和外源调节物质对冻害指数及生理指标的影响,以及有效的冻害预防措施和受冻后的应急技术。研究结果对四川枇杷生态区划和建立成熟期不同的枇杷特色产业带提供了重要依据。更多还原

【Abstract】 In this study, the methods including analysis of field biology, ecology survey, cultivation observation and physiological analysis were used, Sichuan loquat cultivars geographic area (27°-34°N,102°-104°E) including subtropical damp and heat ecotype, southern subtropical semi-dry and hot eco-zone, and southern temperate sub-warm and dry ecotype were investigated. We explored comprehensively the biological characteristics, ecological suitability and the techniques of cultivation and flowering time regulation based on the dominating loquat cultivar Dawuxing. And focused on the ecological effects of loquat growth and formation, yield and quality in different eco-zones, flowering control technology, plastic shed cultivation, and fruit frost damage. The main results were as follows:1. In mid-subtropical damp and heat ecotype, the buds were mainly from the summer shoots with flowering stage concentrated from September to December. The fruit quality was good and maturity of May. Freezing injury and diseases including Sunburn, cracking, shrinking fruit, leaf spot and flower rot were often occurred. In subtropical semi-dry and hot eco-zone, flower could be formed from spring and summer shoots with florescence from June to November. There was no frost damage and fruit stagnant period, the maturity was early during October and next April, but the fruit from the first florescence was small and poor quality. Loquat canker, bud blight and fruit quercus disease should to be prevented. In the valley of southern temperate warm and dry ecotype, the ecological response of loquat was similar to those in less sunshine and humid subtropical eco-zones. The phenophase was late 20-30d with super fruit quality, and panicles were mainly from summer shoots. The amount yield of annual loquat showed a gradual reduction and fruiting branches were mainly from spring shoots with altitude increasing, and the panicles were difficult to be formation and loquat yield could fall sharply by serious chilling injury in some year at altitude more than 1920m with cold temperature of summer and autumn.2. Flowering time regulation was a key factor for achieving economic yield in subtropical semi-dry and hot ecotype. By rational combination of loquat varieties with diverse flowering time and cutting back pruning techniques during middle of February to early April, blooming phase could be regulated and reduced the numbers of early and late flowers. The mature period could be regulated from December to next March with high proportion of good fruit. The techniques of cutting back pruning and the controlling of fertilizer and water were the most effective ways to regulate flowering phase and could most achieve the marketed supply anniversary of loquat in Sichuan.3. In the mid-subtropical damp and heat ecotype, the temperature was higher in plastic shed than that in the open field. The soil temperature was increasing when the air temperature high, but this change scope was less. The plastic film covered on shed ground could increase the soil temperature, and there was not much difference between different films. The relative humidity inside greenhouse was higher than that in open field at the same time. The air temperature higher, the relative humidity was lower, and the changes of relative humidity in open field were greater than that in greenhouse. The soil moisture was highest in film compared to that no film or that exposed in air, and relatively stable at different times. Among the different color films, Silver reflected light strongest with the best light environment. In plastic shed, the late florescence was advanced 5-6 days, mature period was advanced 10 days and spring and summer shoots could be advanced one week and 3-4 days, respectively. Fruit shape was long oval in greenhouse and nearly round in exposed air, the soluble solids and soluble sugar content were decrease for loquat under condition of plastic shed exclude the big volume. However, the two indexes were better in film covering environments compared to that in no film, and not much difference was observed in fruit volume. The incidence of sun scald and fruit shrink disease was increase, rust disease and fruit cracking rate was reduced in the cultivation circumstance of plastic shed.4. Freezing injury often occurred in the mid-subtropical damp and heat ecotype and southern temperate warm and dry ecotype and had become an important limiting factor for loquat economic plantation. The freezing damage in the flatland regions was more serious than that of in slopes by the method of tissue browning, juvenile fruit was tend to injury by freezing than that flowers from different development, and the resistance to cold was best in just flowering and bud tissues. The measures including plastic shed, fruit bagging, shading net and film mulching of tree crown were useful for loquat resistance to freezing damage, and the effect of plastic shed was best. Frost damage most occurred when the minimum temperature less than-0.6℃lasting for above 3 hours with humidity more than 90%. The damage with different degree could be occurred in the flowers and young fruits, and tend to serious with strong frost low temperature and high humidity. Physicochemical index indicated that significant linear correlations were observed between freezing index and SOD activity, and relative electric conductivity in slopes terrain at highly significant level. There was a significant negative correlation between the content of MDA and freezing index at 5% significant level for samples in the flatland, but was not significant compared with that in slope terrain. In addition, the content of proline would increase with temperature decreasing.5. The optimum concentrations of spraying SA and CaCl2 were 90mg/L and 2g/L respectively based on the indexes of frost and physiology. The same physical index was various in different organizes, and there was no significant variance of chlorophyll contents in treatments of diverse chemicals. The biological responses were diverse for different tissues of loquat Dawuxing to frost and exogenous chemicals. The proline content was highest in flowers when spraying the chemical of SA. In the three soaking treatments, the best effect was SA, the better was CaCl2, and the last was CaCl2+K2SO4 based on the analysis of MDA. There was clearly spraying time for some physical index based on same chemicals, but no best spraying phase for exogenous substance in different frosts. The soaking treatment of young fruits in GA (200mg·kg-1)+CPPU (20mg·kg-1) would reduce the effect of freezing damage. The index of fruit shape was increased and numbers of seeds was decreased by spraying GA and CPPU, which could be as the emergency measures when frost occurred.These results obtained from comprehensive investigation would provide valuable information for techniques of cultivation in distinctive ecotypes, and facilitated the economic plantation for loquats in the diverse eco-zones of the world. The behavior of flower formation, condition and relationship with ecological environments was explored and the reason of fruiting several times a year in was made clearly. The techniques of blooming phase regulation could break through the limitation of traditional method and solved the problem of flowers shortage in autumn and beyond enough in summer. The effects of simple shed cultivation on loquat growth, flowering, yield and quality were identified and could be used as reference for protected cultivation. The results of frost study provided climatic insights to freezing damage and physiological indexes of cold hardiness in loquat, which would be useful in preventive and remedial countermeasures of frost injury in loquat plantation.更多还原