Response of Peach, Plum and Almond to Water Restrictions Applied during Slowdown Periods of Fruit Growth

Water restrictions management for fruit rosaceous during slowdown periods of fruit growth can increase water use efficiency and improve fruit quality without reducing significantly their yield. In this context, two water restriction levels were tested during four consecutive seasons (2007-2011) in peach, plum and almond trees during slowdown periods of fruit growth corresponding to stage II for peach and plum and to stages II and III for almond. Water was applied by drip irrigation to produce different water-application treatments of 50% ETc (T50) and 75% ETc (T75) of non-stressed trees irrigated at 100% ETc (T100). The response of trees is presented only for the last season of the experiment (2010-2011) where the effect of the applied water stress is more pronounced. Results show that the effect of water restrictions varied depending on the species. Yield and fruit size were reduced significantly for peach only under treatment T50. Fruit quality was improved for this species with an increase of brix refractometric index and a decrease of acidity. These parameters were evolved in the same manner for plum but the observed differences were not significant. For almond, kernel quality remained unaffected by water restriction at T75. However, the epidermal wrinkles of kernels were more embossed, in response to treatment T50, which affected their appearance. Except leaf area, the evolution of shoots growth, chlorophyll content and leaf temperature showed that the physiology of all species was affected by water stress created by the application of the two irrigation treatments but without profound influence, particularly in plum. In conclusion, irrigation-water may be economized during slowdown periods of fruit growth without major negative effect up to 25% ETc for peach and almond and up to 50% ETc for plum.

Growth simulation and yield prediction for perennial jujube fruit tree by integrating age into the WOFOST model

Mathematical models have been widely employed for the simulation of growth dynamics of annual crops,thereby performing yield prediction,but not for fruit tree species such as jujube tree(Zizyphus jujuba).The objectives of this study were to investigate the potential use of a modified WOFOST model for predicting jujube yield by introducing tree age as a key parameter.The model was established using data collected from dedicated field experiments performed in 2016-2018.Simulated growth dynamics of dry weights of leaves,stems,fruits,total biomass and leaf area index(LAI) agreed well with measured values,showing root mean square error(RMSE) values of 0.143,0.333,0.366,0.624 t ha^-1 and 0.19,and R2 values of 0.947,0.976,0.985,0.986 and 0.95,respectively.Simulated phenological development stages for emergence,anthesis and maturity were 2,3 and 3 days earlier than the observed values,respectively.In addition,in order to predict the yields of trees with different ages,the weight of new organs(initial buds and roots) in each growing season was introduced as the initial total dry weight(TDWI),which was calculated as averaged,fitted and optimized values of trees with the same age.The results showed the evolution of the simulated LAI and yields profiled in response to the changes in TDWI.The modelling performance was significantly improved when it considered TDWI integrated with tree age,showing good global(R2≥0.856,RMSE≤0.68 t ha^-1) and local accuracies(mean R2≥0.43,RMSE≤0.70 t ha^-1).Furthermore,the optimized TDWI exhibited the highest precision,with globally validated R2 of 0.891 and RMSE of 0.591 t ha^-1,and local mean R2 of 0.57 and RMSE of 0.66 t ha^-1,respectively.The proposed model was not only verified with the confidence to accurately predict yields of jujube,but it can also provide a fundamental strategy for simulating the growth of other fruit trees.

Overview of Relation between Mineral Nutrient Elements and Growth and Development of Fruit Trees

Mineral nutrition is the material basis for growth and development,yield and quality of fruit trees. It exerts a great effect on the growth and development,fruit quality,yield,and resistance of fruit trees. On the basis of reading a large number of references both at home and abroad,this paper elaborated the relationship between mineral nutrient elements and growth and fruit yield and quality of fruit trees,so as to make proper fertilizer mixing,balance the fertilizer application,promote growth and development of fruit trees,and increase the yield of fruit trees and improve the fruit quality.

Effects of Different Rootstocks on Plant Growth and Fruit Quality of Watermelon

[Objectives] This study was conducted to explore the effects of different rootstocks on plant growth and fruit quality of watermelon. [Methods] The scions of two different watermelon varieties Qianmei No. 1,which has yellow flesh,and Qianli No. 1,which has red flesh,were grafted onto six different rootstocks of Lagenaria and Citrullus. Then,the seedling survival rate,growth potential and fruit quality in different rootstock-scion combinations were investigated.[Results]Rootstock type showed an extremely significant correlation with the survival rate of grafted watermelon plants. The watermelons grafted onto Lagenaria rootstocks had higher survival rate and better fruit quality than those onto Cucurbita rootstocks. Among them,Jingxinzhenguan was more suitable for red-fleshed watermelon variety,and bottle gourd rootstock was more suitable for yellow-fleshed watermelon variety. There were significant correlations between rootstock type and the number of leaves,the number of branches and the length of main vine of grafted plants. The number of leaves per seedling of all grafted plants was higher than that of non-grafted plants. There were no significant differences in sugar content at the center part of flesh and total soluble sugar content of fruit between the grafted and non-grafted watermelons. In addition,the interaction between rootstock type and watermelon variety had no significant effect on vegetative growth and fruit quality of grafted watermelon. [Conclusions] This study provides a theoretical basis for the grafting of watermelon.

Effects of Different Irrigation Methods on Growth,Fruit Quality and Yield of Apple Trees

Water-saving irrigation is an important way to realize the sustainable development of the apple industry.In order to screen the best irrigation pattern for apple,taking 9-year-old‘Yanfu 10'Fuji/Malus robusta apple as the material,the effects of different irrigation methods(drip irrigation,sprinkling irrigation,and flood irrigation) on the growth,fruit quality,and yield of apple trees were studied.The results showed that compared with the flood irrigation,drip irrigation and sprinkling irrigation significantly increased the spring shoot length by 14.8%and 9.1%,respectively,and decreased the autumn shoot length by 11.7% and 8.8%,respectively.Drip irrigation and sprinkling irrigation significantly increased the leaf area,chlorophyll content,and leaf weight,the leaf area increased by 3.0% and 1.9%,respectively,the chlorophyll content increased by 13.9% and 11.5%,respectively,and the leaf weight increased by 5.8% and 5.1%,respectively.Drip irrigation and sprinkling irrigation could slightly increase the single fruit weight and fruit shape index,significantly increase the coloring index and smoothness index.The single fruit weight increased by 3.2% and 1.9%,the coloring index increased by 6.1% and 4.1%,the smoothness index increased by 4.7% and 2.8%,and the proportion of red fruit increased by 4.2% and 2.2%,respectively.The content of soluble solids in drip irrigation and sprinkling irrigation was significantly higher than that in flood irrigation,which was 13.0% and 2.6% higher than CK,respectively.The fruit hardness in drip irrigation and sprinkling irrigation was 7.9% and 2.2% higher than CK,respectively,and that in drip irrigation increased significantly.The yield in drip irrigation and sprinkling irrigation was 12.1% and 8.2% higher than CK,respectively.In conclusion,drip irrigation and sprinkling irrigation could promote the growth of apple trees,improve the fruit quality,and increase the yield of apple trees,and the effect of drip irrigation is better than sprinkling irrigation.

Effects of Different Density-reducing Methods on Canopy Microenvironment, Tree Growth and Fruit Quality in Closed Apple Orchard

In order to optimize and transform closed mature apple orchards with standard rootstocks and improve the quality of fruit,taking a closed Red Fuji apple orchard as the test object,the effects of different density-reducing methods(deinterlacing,removing every other plant in each row,removing every other plant every other row)on the canopy microenvironment,tree structure,leaf photosynthesis and fruit quality were studied.The results showed that different density-reducing methods significantly reduced the orchard coverage and increased the crown transmittance.Among them,the deinterlacing treatment was the best in improving the population structure of the closed orchard,as it reduced the orchard coverage rate by 55.68 percentage points and the canopy transmittance by 82.38 percentage points,compared with the control(CK).Different density-reducing methods all could significantly reduce the branch amount in the closed orchard and optimized the branch composition.The three density-reducing methods decreased the number of branches per plant by 18.96%,12.41%and 19.58%,respectively,compared with the CK.And compared with the CK,the proportion of short branches and leafy branches to the total branches was increased by 17.13%,14.27%and 7.37%,respectively,and the proportion of long branches and developmental branches to the total branches was decreased by 24.47%,18.04%and 10.79%,respectively.The effects of the different density-reducing methods on the temperature,relative light intensity,SPAD and leaf photosynthetic rate in canopies all followed an order of deinterlacing>removing every other plant in each row>removing every other plant every other row>CK,while those on the relative humidity showed an order of deinterlacing>removing every other plant in each row>removing every other plant every other row>CK,while those on the relative humidity showed an order of deinterlacing<removing every other plant in each row<removing every other plant every other row<CK.The average single fruit weight(238.3 g),coloring index(89.2),smoothness index(83.2),soluble solid content(15.1%)and high quality fruit rate(82.4%)of the deinterlacing treatment were higher than those of other treatments,and the values were 18.2%,11.4%,5.85%,26.9%and 25.2%higher than the CK,respectively.The use of dein￣terlacing to reduce density is the best for improving the microenvironment of closed apple orchards and improving the photosynthetic efficiency and fruit quality.

Vegetative Development of <i>Sparassis crispa</i>in Various Growth Conditions and Effect of Electric Pulse Simulation on Its Fruit Body Production

This study was carried out to detect the favorable mycelial growth conditions and effect of electric pulse stimulation on fruit body production of SC-1 strain of Sparassis crispa. The optimum growth in PDA was found at 25°C (67 mm colony diameter in 28 days) followed by 20°C (63 mm colony diameter in 28 days). There was no mycelial growth at 35°C. The most favourable initial media pH range was found to be 5 - 7 and colony diameter measurements were not statistically different among these pH values (p > 0.05). However, the highest growth was obtained at pH 6 (57 mm colony diameter in 28 days). A basal medium composed of 0.05 g MgSO4, 0.46 g KH2PO4, 1.0 g K2HPO4, 120 μg thiamine-HCl, 20 g agar and 1000 ml of distilled water was used to investigate growth response of S. crispato different carbon and nitrogen sources. In 28 days, fructose and glucose exhibited best growth (49.4 mm and 31.6 mm colony diameters respectively) and there was no growth on the basal medium supplemented with galactose. Basal medium supplemented with glycine and alanine as nitrogen sources resulted in best growth, 54.4 mm and 50.5 mm colony diameters respectively. There was no mycelial growth in culture medium supplemented with ammonium acetate, ammonium phosphate, arginine and histidine. Electric pulse stimulation improved the fruiting body production. The yields obtained from all bottles in which electric pulse was applied were significantly higher than the yields from the bottles in which electric pulse was not applied. The percent increases of fresh weight yield from control on 100, 120, 130, and 170 kilovolts were 36%, 44%, 75% and 81% respectively. As regard to dry weight yield, the percent increases from control on 100, 120, 130, and 170 kilovolts were 27%, 54%, 63% and 67% respectively.

广西沃柑果实横径生长动态及模型构建

【目的】研究广西沃柑果实横径的生长动态并构建数学模型,为提升其品质和产量提供科学依据。【方法】以沃柑为材料,于稳果后,连续两年每月1日、15日通过“定园、定点、定果、定期”的方法测量并记录广西桂南、桂中、桂北15个果园的沃柑横径数据,直至采收期,研究沃柑横径的变化动态,考察年终横径与各生长节点,月度横径增加值与主要气象信息的相关性并建立数学模型。【结果】各个果园最终的横径差别较大,达到极显著差异水平,多个果园的横径有待提升;对比气象数据,选定2021—2022年度的沃柑横径数据为正常年份数据,翌年1月15日果实横径平均值为69.85 mm,最高的果园达75.33 mm,最小的61.55 mm;以80、75、70、65、60、55 mm为等级,构建桂南、桂北和桂中沃柑果实横径生长动态对照表、横径月度增加值对照表;分别建立年终沃柑横径数值与各生长节点,横径月度增加值与主要月度气象信息的数学模型,年终横径与7月15日呈显著正相关,与8月15日以后呈极显著正相关,至11月1日达到极显著的0.934 0;月度增加值与降雨、温度相关系数分别为显著的0.791 8和极显著的0.879 1。【结论】广西沃柑提质增产仍存在较大空间,可结合当期横径生长对照表、定期差值对照表,科学合理安排水肥药的灌溉来进一步加速果实膨大,从而提升效益。

螯合钙叶面肥及遮阳网对番茄果实生长的影响

为探究叶面喷施螯合钙+遮阳网对温室春延茬番茄果皮代谢特征、果实裂果和品质的影响,以优品88番茄品种为材料,分别进行了CK(未遮阳+叶面喷施清水)、CC(未遮阳+叶面喷施0.30 g·L^(-1)螯合钙)、S(遮阳网+清水)与SCC(遮阳网+0.30 g·L^(-1)螯合钙)的处理试验。结果表明,转色期与红熟期番茄果实裂果率均表现为SCC<S<CC<CK,且各处理间差异显著;与CK相比,CC、SCC处理均显著提高了果皮超氧化物歧化酶与抗坏血酸过氧化酶活性,降低了果皮丙二醛和H2O2含量;CC、S与SCC处理均显著降低了果皮细胞壁水解酶活性;果皮纤维素与原果胶含量呈现SCC>S>CC>CK的变化趋势,且SCC处理与其他各处理呈显著差异;CC与SCC处理均显著提高了果实单果质量、维生素C和可溶性固形物含量,且SCC处理效果最好。综上所述,在温室番茄生产中,0.30 g·L^(-1)螯合钙+遮阳网协同作用的增产提质效果最优。

基于3种非线性回归模型的薄壳山核桃果实生长发育研究

以波尼、马汉、卡多、赛普洛斯、贝壳等薄壳山核桃品种为试验对象,定期对核桃果实的纵径、横径的生长量进行观测,通过果实解剖掌握果实的发育阶段,最后分别应用Logistic模型、二次多项式、三次多项式对果实的两径数据进行拟合。结果表明:各品种果实的两径生长均呈现出典型的“S”形曲线,且纵径的累计生长量始终大于横径;三次多项式对果实的两径拟合效果均优于Logistic模型和二次多项式,其中三次多项式的拟合系数均超过0.991,且与实测数据的相关性均达到极显著水平,表明三次多项式能够更好地拟合薄壳山核桃果实的发育过程。拟合方程可确定不同品种果实发育的各个时间节点,结合果实解剖结果,可揭示各品种果实的发育进程。

不同供钙水平下外源硅对辣椒生长及果实品质的影响

以辣椒品种“奥黛丽”为试材,采用基质盆栽的方式,设置4个不同供钙水平(1.5、1.0、0.5、0 mmol·L^(-1)Ca)和2个外源硅肥水平(1.5、0 mmol·L^(-1)Si),二者完全随机组合,共8个处理,研究了不同供Ca水平下施Si对辣椒生长及果实品质的影响,以期为设施辣椒优质高效肥料配施提供参考依据。结果表明:随供Ca水平的降低,辣椒幼苗的株高、茎粗与生物量积累逐渐下降,施加外源Si均不同程度促进了各水平下幼苗的生长;低Ca水平下,幼苗叶片的叶绿素含量、净光合速率、蒸腾速率、胞间CO_(2)浓度及气孔导度均不同程度下降,施Si显著缓解了低Ca水平对辣椒光合作用的抑制;随着供Ca水平的降低,辣椒的果实产量显著降低8.15%~73.23%(P<0.05),施Si则不同程度缓解了低Ca对辣椒产量的抑制;随供Ca水平的降低,辣椒果实的营养物质含量逐渐下降,施Si则显著改善了低Ca下辣椒的果实品质。因此,供Ca水平的降低会显著抑制辣椒生长发育及光合作用,降低果实的品质及产量,施加外源Si均可不同程度缓解低Ca胁迫对辣椒的伤害。

澳洲坚果‘O.C’果实发育及品质变化规律研究

为探究澳洲坚果果实生长和品质的变化规律,以6 a生‘O.C’为试材,于盛花期挑选状态基本一致的花序进行标记,跟踪测定果实横纵径、果形指数、单果质量、内果皮颜色、单壳果干质量、单果仁干质量、出籽率、出仁率、一级果仁率、粗脂肪、蛋白质、可溶性总糖及脂肪酸含量,对内果皮颜色及果实评价指标进行相关性分析,并采用主成分分析法对不同发育时期的果实品质进行综合评价。结果显示:(1)澳洲坚果果实横纵径、单果质量的生长趋势基本一致,呈“快速—缓慢—稳定”的“S”形曲线,果形指数呈近似“L”形。(2)花后105~195 d,内果皮颜色L^(*)值逐渐降低,a^(*)/b^(*)逐渐上升;壳果横纵径差异不显著;单壳果干质量、单果仁干质量、出仁率、一级果仁率、粗脂肪及蛋白质含量逐渐升高至稳定;出籽率、可溶性总糖含量呈下降—升高—稳定的变化趋势;不同发育时期的果仁中均检测出12种主要的脂肪酸,包括6种饱和脂肪酸、4种单不饱和脂肪酸和2种多不饱和脂肪酸。(3)相关性分析表明,39对性状呈极显著水平,16对性状呈显著水平,大多数品质指标间具有较强的相关性,且内果皮颜色与品质指标关系密切。(4)利用主成分分析法对果实品质进行综合评价,不同发育时期综合得分(Dn)的变化范围为-1.565~0.727,花后175 d的果实排名第一。结果表明,花后175 d为澳洲坚果‘O.C’的最佳采收时期,内果皮颜色的L^(*)值在35.73以下、a^(*)/b^(*)在1.48以上可作为该品种集中采收期确定的重要参考指标,研究结果为澳洲坚果‘O.C’丰产栽培及适时采收提供了理论依据。

全生物降解地膜对湖南不同地区果蔬生长的影响

针对塑料地膜使用造成土壤环境污染的问题,研究以白色/黑色全生物降解地膜和普通塑料地膜为参试材料,在湖南省长沙市、沅江市、汉寿县等地区开展了西瓜、莴苣、秋葵等作物的覆膜试验,探究全生物降解地膜对不同作物的生长、品质、产量及土壤性质等指标的影响,观察全生物降解地膜的降解情况。结果发现,两种全生物降解地膜对湖南各地区果蔬生产均起到提质增效的作用。沅江地区黑色降解地膜覆盖栽培西瓜,西瓜单瓜重增加25.8%,叶片数增加45.5%,显著高于未覆膜处理;覆盖白色降解地膜的秋葵叶片长度比对照高42.1%,叶片宽度比对照高55.9%,叶片数增加43.2%,产量增加55.5%。普通塑料地膜在作物收获后未能降解,白色和黑色全生物降解地膜的降解率分别为80.3%~90.7%和63.0%~80.3%。综合不同地区的试验结果,认为两种降解地膜均可作为普通塑料地膜的潜在替代品,具有较大的推广前景。

4种不同果形香花油茶果实生长动态变化分析

【目的】为了更好地指导香花油茶生产。【方法】选取4种不同果形香花油茶无性系68号(橄榄形)、70号(球形)、84号(桔形)、91号(卵形),对香花油茶果实生长发育动态变化进行观测和分析。【结果】1)香花油茶不同无性系果实迅速膨大开始和结束时间均有明显差异。68、70和91号无性系果实体积迅速膨大均始于7月15日,其中70号无性系果实迅速膨大在8月5日结束,期间果实增幅达到8.82 cm^(3),占观测期体积总生长量的50.66%;68和91号无性系在8月25日结束果实迅速膨大,期间体积分别增长了5.47和8.71 cm^(3),分别占观测期体积总生长量的57.07%和51.96%。84号无性系果实体积迅速膨大始于8月5日,并一直持续到10月15日,8月5—25日及8月25日—10月15日期间果实体积增长分别占比34.52%和37.63%。2)果实中籽粒转黑时间与果实结束快速生长期的时间存在相关性,快速生长期结束时间早,籽粒转黑的时间也早。【结论】香花油茶不同无性系果实生长进程存在明显差异,果实迅速膨大关键期主要集中在7月15日—8月25日。

果胶酶提取西番莲果皮多糖的抗氧化和益生菌增殖活性

该文以西番莲果皮为原料,采用酶法辅助提取果皮多糖并对其抗氧化和益生菌增殖活性进行研究。通过正交试验优化西番莲果皮多糖提取参数;通过测定其还原能力,及对DPPH自由基和羟自由基的清除率来考察其抗氧化活性;将西番莲果皮多糖作唯一碳源,研究其对植物乳杆菌(Lactobacillus plantarum)、德氏乳杆菌保加利亚亚种(L.delbrueckii(subsp.)bulgaricus)、短乳杆菌(L.brevis)和嗜热链球菌(Streptococcus thermophilus)的体外增殖作用。结果表明,提取条件为:果胶酶添加量5 mg/mL,pH 4.5,提取时间2 h,提取温度40℃,此条件下,多糖得率为15.83%。西番莲果皮多糖有较好的还原能力,并对DPPH自由基和羟自由基有较好的清除率,呈现剂量依赖关系。西番莲果皮多糖对上述4种菌均有一定的增殖作用,最大生长速率排序为:植物乳杆菌(0.1599)>嗜热链球菌(0.1395)>短乳杆菌(0.1251)>德氏乳杆菌保加利亚亚种(0.1239)。西番莲果皮多糖是一种天然的食品抗氧化剂和益生元物质,有很好的市场前景。

不同生长期瓦尼桑黄和粗毛纤孔菌子实体主要活性成分含量比较

测定比较瓦尼桑黄和粗毛纤孔菌子实体不同产地及不同生长期粗多糖、总黄酮、总三萜、麦角甾醇的含量,结果表明,相同培养条件下,粗毛纤孔菌子实体在180 d采收时粗多糖含量最高,为4.52%;在60 d采收时总黄酮和麦角甾醇含量最高,分别为5.23和34.03 mg/kg;在30 d采收时总三萜含量最高,为0.61 mg/kg。3年生椴木栽培瓦尼桑黄子实体总三萜和麦角甾醇含量分别为0.17和5.86 mg/kg,显著高于1年生子实体总三萜和麦角甾醇含量(0.06和1.90 mg/kg)。综合比较,粗毛纤孔菌子实体活性成分含量优于瓦尼桑黄子实体。

植物生长调节剂对甜樱桃果实发育及内源激素动态变化的影响

以7年生萨米脱甜樱桃为试材,研究甜樱桃果实、果柄生长发育及内源激素含量的变化趋势,并探讨GA_(3)+6-BA处理对果实、果柄生长发育及内源激素含量变化的影响。结果表明:甜樱桃果实生长发育期内,果实重量相关性状中单果重、果实纵径和果实横径的动态模型符合Logistic方程,果实重量最大相对生长速率出现的时间在花后28 d左右,果实中ABA、GA_(3)、IAA、ZR含量均呈先下降后上升的变化趋势,果柄与果实内源激素含量变化趋势并不协同;GA_(3)+6-BA配施处理后,促进了甜樱桃果实及果柄的生长,使内源激素IAA、GA_(3)、ZR的含量显著增加,并显著增加了果柄(GA_(3)+ZR+IAA)/ABA值。研究结果为植物生长调节剂在甜樱桃上的应用提供了一定的理论参考依据。

9个粉(白)果草莓品种在贵州贵阳栽培比较试验

为筛选出适宜贵州省贵阳地区栽培的粉、白果草莓品种,丰富贵阳地区栽培草莓品种结构,促进贵阳地区草莓产业发展。以9个粉、白果草莓品种为试材,观察物候期,测定植株生长指标及果实品质、产量,比较不同品种在贵阳地区的栽培表现。结果表明:粉玉产量高,硬度最大,可溶性固形物含量高,风味酸甜可口,有香气,口感佳;小白果实成熟期最早,可溶性固形物、可滴定酸含量最高,有香气,风味浓郁酸甜;淡雪果面粉色,果肉浅粉色,可溶性固形物含量、固酸比较高,白粉病病果率低。根据产量、可溶性固形物含量、固酸比、白粉病病果率4个性状的加权得分建立草莓品种筛选标准,筛选出在贵阳地区具有推广前景的草莓品种有粉玉、小白、淡雪。

杏果实发育过程中果胶组分及酶活性变化分析

【目的】研究杏果实发育过程中果胶组分及含量变化规律及其对果实硬度的影响。【方法】以‘库车白杏’、‘轮台白杏’和‘树上干杏’3个杏品种果实为材料,测定杏果实发育过程中的生长品质指标、果胶组分与含量和果胶代谢酶活性,分析杏果实果胶组分及含量变化且与果实硬度之间的相关关系。【结果】相较于其他4个生长发育期,3个杏品种果实硬度在完熟期显著下降(P<0.05)。果实发育成熟过程中,3个杏品种果胶甲酯酶活性(PME)均呈下降趋势,且果实硬度与PME呈显著正相关(P<0.05),果实硬度与离子结合型果胶含量、共价结合型果胶含量呈极显著负相关(P<0.01)。【结论】果实发育过程中,3个杏品种果实硬度均与离子结合型果胶含量、共价结合型果胶含量呈极显著负相关(P<0.01),对果实硬度影响较大。其中离子型果胶(ISP)分子量小,易溶于水,在果胶中,ISP占比越大,果实质地越软;‘轮台白杏’与‘树上干杏’硬度下降主要是由多聚半乳糖醛酸酶(PG)引起的,而‘库车白杏’硬度下降主要是由果胶裂解酶(PL)引起的,其中‘轮台白杏’自硬核期开始多聚半乳糖醛酸酶(PG)活性升高,硬度随之下降;但在‘树上干杏’中,多聚半乳糖醛酸酶(PG)活性在幼果期之后甚至显著下降,在转色期之后显著上升,硬度随之下降。对‘轮台白杏’需要在硬核期之后开始抑制多聚半乳糖醛酸酶(PG)活性,对‘树上干杏’需要在转色期后抑制多聚半乳糖醛酸酶(PG)活性。‘库车白杏’果胶裂解酶(PL)活性一直较高,在果胶方面其需要抑制果胶裂解酶(PL)活性。

不同果实生长期亏缺灌溉对渭北苹果生长、品质及水分利用效率的影响

【目的】探索节水、控水方式调控苹果水分高效利用效率的机制,优化渭北苹果主产区节水、丰产和增收的管理方式。【方法】以陕西省咸阳市乾县铁佛镇果友协会试验站8年生‘烟富3号/T337’苹果树为试材,设置充分灌溉(灌溉后土壤相对含水量为75%)和轻度亏缺灌溉(灌溉后土壤相对含水量为50%)2个灌水量水平,组成果实生长期和膨大期均充分灌溉(CK)、果实生长期和膨大期均轻度亏缺灌溉(W1)、果实生长期轻度亏缺灌溉和膨大期充分灌溉(W2)及果实生长期充分灌溉和膨大期轻度亏缺灌溉(W3)4个灌溉模式处理,测定春梢生长指标、果实品质指标和果实产量指标,计算水分利用效率、灌溉水利用效率、果实综合评价满意度,以明确最佳的亏缺灌溉方式。【结果】(1)苹果新梢长度及叶片叶绿素相对含量(SPAD)在各处理间无显著性差异,而其春梢直径在各处理下显著降低。(2)与CK相比,单果质量在W1处理下显著降低了10.3%,果实可滴定酸含量在W2处理下显著降低14.7%,果形指数和可溶性固形物含量在3种水分亏缺灌溉处理下均无显著变化。(3)W1处理能显著提高果皮黄色值b*,W2处理能显著提高果皮色泽饱和度C*,而各亏缺灌溉处理对果皮亮度值L*和红绿值a*均无显著影响。(4)与CK相比,果实产量在各亏缺灌溉处理下降低13.4%~24.7%,但仅W1处理降幅达显著水平;果树灌溉水利用效率在各亏缺灌溉处理均不同程度提高,但仅W1处理显著提高了38.0%;果树耗水量和水分利用效率在各亏缺灌溉处理下无显著性差异。(4)果实综合评价满意度表现为W2>CK>W3(W1)。【结论】陕西渭北地区苹果在生长期轻度亏缺灌溉和膨大期充分灌溉(W2)模式下果实的综合评价满意度最高,果实产量、单果重无显著变化,而果实品质较优,果树水分利用效率较高。