以云南9个不同栽培区域'哈斯'(Hass)油梨果实为试材,在同一条件下分别观测油梨果实主要内在与外观品质,分析云南不同栽培区域油梨果实主要品质差异,为探索云南油梨栽培适宜生态区域提供借鉴.结果表明:(1)油梨果实外观品质以单果重、种子重量、可食率变异系数较大,分别达到31.31％、38.09％和8.08％,并以LJ产区的油梨单果重和可食率最大;油梨果肉内在品质中以脂肪、可溶性蛋白、维生素C(Vc)含量变异系数较大,分别为37.57％、22.42％和17.89％,脂肪含量以BS产区最高,可溶性蛋白和Vc含量均以BN产区最高.(2)油梨果实Vc、总黄酮、脂肪含量以及单果果肉重、果实纵径等显著受到树龄和气候因子的综合影响.其中:树龄与脂肪、可溶性固形物、Vc、总黄酮含量呈正相关关系,与单果果肉重呈显著负相关关系;经度与脂肪、可溶性固形物、干物质、可溶性蛋白含量呈正相关关系;纬度与可溶性固形物、果肉密度、种子长度呈正相关关系,与Vc、总黄酮含量呈显著负相关关系;海拔与脂肪、可溶性固形物、Vc、总黄酮含量呈正相关关系;年平均气温与果肉密度、单果重、单果果肉重、果实纵径呈正相关关系;年平均降雨量与脂肪、可溶性固形物含量呈正相关关系;年平均日照时数与脂肪、Vc、总黄酮含量呈正相关关系.(3)果实外观品质、脂肪、总黄酮和干物质含量等指标是评价云南油梨果实品质的重要因子,这4个主成分的累积方差贡献率达68.955％;油梨品质因子综合分析得分排名前3位的产地依次是保山市潞江坝镇(LJ)、龙陵县(LL)、保山(BS),分别达到0.833、0.611和0.551.(4)云南9个产地油梨果实可聚类划分为3类,第Ⅰ类为耿马县(GM)、永德县(YD)、元谋县(YM)、芒市遮放镇(ZF)产区,该类油梨果实大小中等、种子偏小、可食率高且干物质、Vc、可溶性蛋白含量高;第Ⅱ类为景洪市(BN)、芒市轩岗乡(XG)产区,该类油梨果实偏小、种子小、可食率高且Vc、可溶性蛋白、总黄酮含量相对较高,而干物质和脂肪含量相对偏低;第Ⅲ类为LJ、LL、BS产区,该类油梨果实大、果肉多、肉质厚、种子大且脂肪、干物质、Vc、可溶性蛋白、总黄酮含量高,综合品质最好.研究认为,云南油梨果实品质在不同产地间存在显著差异,并显著受到树龄与生态因子的综合影响.

Internal browning（IB） seriously restricts the development of pineapple industry. Its occurrence is mainly from excessive reactive oxygen species（ROS） causing membrane damage, which breaks the original compartmentalization between plastid polyphenol oxidase（PPO） and phenolic substrates in vacuoles. It polymerizes into quinones after contact with oxidation. The antioxidant clearance system is able to remove excess ROS and maintain the dynamic balance of ROS in the body. In early time, our laboratory used ascorbic acid（AsA） which can effectively delay the deterioration of IB of ‘Pairs’ pieapple. But the reaction mechanism of AsA is not clear. Ascorbate peroxidases（APX,EC1.1.11.1） are heme-binding enzymes that reduce hydrogen peroxide（H2O2） to water using AsA as an electron donor.It is involved in various developmental physiological processes and stress responses in plants. In this study, we selected six APX genes with AsA as the substrate in pineapple to analyze the occurrence process and the ascorbate transcript level changes after the AsA treatment. AcAPX1 was significantly upregulated at 9 d and 12 d after AsA treatment and was significantly different from the control group. It showed that AsA significantly enhanced the AcAPX1 expression.Correlation analysis showed that the incidence index of black heart disease was significantly positively correlated with the AcAPX1 expression level. It is speculated that this gene may play an important role in AsA delaying IB with pineapple. To further explore the mechanism of action, AcAPX1 was cloned from the pineapple pulp. The physicochemical properties and protein domain were analyzed by bioinformatics analysis. The results showed that the open reading frame length was 753 bp, encoding 250 amino acids. The predicted molecular weight of the protein was 27.410 87 kDa, and the theoretical isoelectric point was 5.52. There was no transmembrane helix region, which was a stable hydrophilic protein.Amino acid sequence alignment analysis showed that AcAPX1 of pineapple shared more than 85% homology with papaya,banana, coconut and oil palm. The functional domain analysis of AcAPX1 showed that it had heme binding sites, K + binding sites and substrate binding sites（superfamily: cl00196）, belonging to the members of the plant peroxidase superfamily.Cloning of AcAPX1 is of great significance for studying the molecular mechanism of its antioxidant capacity in pineapple and the control of internal browning. This study would lay a foundation for further exploring the molecular mechanism of pineapple AcAPX1 involved in AsA clearing ROS and delaying the deterioration of internal browning.

叶绿素降解是果实色泽形成过程中一个主要的影响因素.脱镁叶绿素酶(pheophytinase,PPH)是叶绿素降解代谢的关键酶.本研究提取杧果果皮总RNA,采用RACE方法,克隆得到一个脱镁叶绿素酶基因,并对其进行了初步的生物信息学分析.序列分析表明MiPPH基因cDNA序列全长1 267 bp,开放阅读框为1 113 bp,可编码370个氨基酸,分子量为41.73 kD,等电点为5.22.使用NCBI上的Conserved domains分析MiPPH蛋白结构域,结果显示MiPPH含有PLN02578、Abhydrolase_1共2个结构域,其中PLN02578为保守域,其他物种PPH也都含有这个水解酶(Hydrolase)保守域,说明PPH蛋白有高度的保守性.通过BLAST上其他植物的氨基酸序列进行相似性比对,利用DNAMAN生成的系统进化树发现杧果MiPPH蛋白序列和与同为漆树科的开心果的PPH蛋白序列相似度较高,亲缘关系较近.利用定量PCR技术对不同品种中的MiPPH基因表达量进行分析,发现绿色'桂七'品种表达量最高,而黄色'金煌'品种表达量最低,黄色'金煌'品种和红色'贵妃'品种表达量相差不大.本试验成功构建pCAMBIA2300-GFP-MiPPH植物表达载体,通过农杆菌介导的烟草瞬时表达,亚细胞定位MiPPH主要定位于细胞核.本试验为后续进行PPH基因的功能验证提供试验基础.

Avocados are a type of tropical fruit with high nutritional, health and economic value. In this study, the main cultivar, Hass, which has brown skin at maturity, and the self-bred variety Hongyou1#, which has red skin at maturity, were used as the test materials. The dynamic changes in the main skin pigments of the two varieties during different color change periods after harvest were observed. Additionally, metabolomics and transcriptomics were used to analyze the differences in anthocyanin metabolites and gene expression between the two types of avocados during the skin coloring process. Moreover, the initial coloring mechanism of avocado fruit skin was explored. The results showed that the pigments that mainly accumulated during the peel coloring process of both types of avocados were anthocyanins, and their main derivatives were cyanidins. The accumulation of cyanidin-3-O-rutinoside in Hongyou1# led to their different colorations. The structural genes F3H, DFR, ANS, UFGT, LAR, and ANR and transcription factors MYB and bHLH, which control the synthesis of cyanidins in the anthocyanin synthesis pathway of both kinds of avocado peels, were significantly differentially expressed during the coloring process and played important roles in cyanidin regulation. Joint analysis showed that cyanidin-3-O-rutinoside was positively correlated with transcripts in Hongyou1# and negatively correlated with those in Hass. Thus, we speculate that the expression of related genes in Hass inhibited the synthesis of cyanidin-3-O-rutinoside in this type of avocado.

本研究利用转录组数据对荔枝的PG基因家族进行分析,以探究PGs基因在荔枝中存在的形式,及荔枝PG基因家族在荔枝果实衰老中的作用及表达规律.结果表明,(1)荔枝中存在21个PG基因家族成员,它们的理化性质差异较大,多数蛋白表现为酸性及亲水性,位于细胞外基质或细胞质膜上.(2)该基因家族成员都存在保守基序8和保守基序14,结构域SPNTDG(Ⅰ)、GDDC(Ⅱ)和RIK(Ⅳ),但缺失了结构域CGPGHG(Ⅲ).(3)进化树显示该基因家族成员分为5个类群,其中GroupⅢ是主要类群,其他类群在进化过程中逐渐形成.(4)RT-qPCR结果表明该基因家族的蛋白在荔枝生长发育过程中发挥不同作用,研究发现PG3、PG12、PG15、PG21与果实的衰老有关,表达量随果实衰老进程加剧而不断升高,它们正向调控了果实的衰老.本研究初步探究了 PG基因家族成员在荔枝果实衰老过程中的作用,找出了几个和果实衰老相关的PG基因,为进一步研究荔枝的生理提供参考.

Phytoene desaturase (PDS) affects the synthesis of carotenoids. It is a key gene in the carotenoids biosynthesis pathway. In order to study the function of PDS gene from mango fruits, the phytoene dehydrogenase ( PDS ) gene of ‘Guifei’ mango fruit was obtained with RACE methods. The full-length cDNA sequence of the gene is 1 820 bp, open reading frame is 1 650 bp, encoding 549 amino acids, the molecular weight is 61.34 KD, and the isoelectric point is 6.78. It was cluster analysis found that the mango PDS protein had a close relationship with grapefruit, cantaloupe, and papaya. Its amino acid composition is mainly alanine (ALa), leucine (Leu), valine (Val), and so on. Expression of PDS gene in different varieties by PCR showed: the high expression of the red ‘Guifei’ varieties and the expression of green mango varieties with low volume. Prediction of the domain, tertiary structure, and interaction protein of its protein, found to contain phytoene-desat, PLNO2487 superfamily, and other domains. The use of the STRING database found PDS interacted with proteins such as PSY, ZDS, and CRTISO. This research will be valuable for understanding the molecular mechanism of gene regulation in carotenoid biosynthesis and can be served as the basis for the metabolic engineering of mango.

以6年生‘珍珠’番石榴果实为材料，于谢花后15 d开始，果面分别喷施6.25、12.5、25、37.5、50 mg/L的5-ALA，以探究不同浓度5-ALA对成熟期番石榴果实品质的影响。结果表明：（1）外源喷施ALA可同时显著提升番石榴果实横径和纵径，从而显著提升果实单果重，对果实纵径提升幅度大于横径幅度，但果形指数无显著变化。（2）外源喷施ALA可提高番石榴果实TSS含量、可溶性糖含量、VC、可溶性蛋白和总酚的含量，同时可在一定程度上降低果实可滴定酸含量。所试浓度中，以25 mg/L ALA处理番石榴果实TSS、可溶性蛋白和VC含量最高，37.5 mg/L ALA处理可溶性糖含量最大，6.25 mg/L ALA处理降低果实可滴定酸效果最佳，该处理糖酸比显著高于其他浓度处理。（3）模糊隶属函数综合分析表明，本试验所设浓度中以25 mg/L ALA处理综合处理效果最佳。由此可见，外源ALA可以有效促进番石榴果实品质的提升，但对番石榴果实品质影响存在浓度效应，提升不同品质指标的最佳浓度各异。本试验初步探究了ALA对番石榴的品质影响，确定25 mg/L ALA有较好的效果，为进一步研究海南‘珍珠’番石榴品质提升提供参考意义。

为评价不同品种(系)油梨果实品质差异,以富尔特、桂研10号、GYL-1、GYL-2、GYL-3为试验材料,测定其单果重、果实横径、果实纵径、果形指数、可食率、含水量、可溶性固形物含量、可滴定酸含量、可溶性蛋白含量、固酸比、维生素C含量和粗脂肪含量共12个品质指标,利用模糊数学隶属函数、相关性分析、主成分分析和聚类分析,客观、准确地分析油梨果实品质的差异.结果表明:①不同品种(系)油梨果实品质性状差异明显,变异系数在4.39％～40.68％之间,以粗脂肪含量的变异程度最大,含水量变异程度最小.②通过隶属函数值分析,不同油梨品种果实品质优劣依次表现为GYL-2＞富尔特＞桂研10号＞GYL-1＞GYL-4.③主成分分析表明,前4个主成分的累积贡献率达到100％,决定第1主成分的主要为可滴定酸含量、含水量、可溶性蛋白含量和可溶性固形物含量;决定第2主成分的主要为粗脂肪含量、维生素C含量、固酸比和可食率;果形指数和果实纵径对第3主成分的贡献率最大;第4主成分主要反映指标维生素C含量;根据主成分分析的综合分值,不同品种(系)排名为GYL-2＞富尔特＞桂研10号＞GYL-1＞GYL-4.④聚类分析结果显示,5个油梨品种(系)被分成3类,其中GYL-2、富尔特、桂研10号的果实品质优于GYL-1和GYL-4.综上,隶属函数法、主成分分析和聚类分析结果基本一致,即品种GYL-2果实品质最好,富尔特次之,GYL-4最差.研究结果揭示了5个油梨品种(系)果实品质的差异,建立了一套适合油梨果实品质评价的方法,为贵州油梨产业可持续发展奠定理论基础.

用23对SSR多态性引物对收集的54份油梨种质材料进行PCR扩增,利用Popgene 1.32计算遗传多样性参数,采用NTSYSpc 2.1计算种质间的遗传相似系数,并进行UPGMA聚类分析和主成分分析.结果表明,23对SSR引物共扩增出多态性位点119个,每对引物扩增的多态位点在2?10个之间,平均为5.17个,多态性位点百分比(PPL)为100％;多态性信息量(PIC)、有效等位基因数(Ne)、Nei's基因多样性指数(H)、Shannon's信息指数(I)分别为0.33、1.321 9、0.205 9、0.335 60 54份油梨种质资源的遗传相似系数在0.59～0.97之间,在0.71处可划分为4大类群,Fuerte单独归为第Ⅰ类,Hass、Bacon为第Ⅱ类,第Ⅲ类的种质包括Yl-10、Y3-1、Y6-5、Y10-1,余下47份归为第]类,占参试材料的87.04％,主成分分析结果与聚类分析结果基本一致.

基于ISSR分子标记技术分析油梨种质遗传多样性和亲缘关系,旨在为油梨种质资源的合理利用提供科学依据.选用12条ISSR多态性引物对54份油梨种质的基因组DNA进行PCR扩增,利用Popgene 1.32、NTSYSpc 2.1软件计算遗传多样性参数、种质间的遗传相似系数以及UPG-MA聚类分析.结果显示,筛选出的12条ISSR多态性引物共扩增出106条谱带,平均每条引物扩增8.08条多态性谱带,多态性位点比率PPB为91.83％,平均观测等位基因数(Na)、有效等位基因数(Ne)、Nei's基因多样性指数(H)、Shannon's信息指数(I)以及多态性信息量(PIC)分别为1.89、1.47、0.28、0.43、0.63.油梨种质间的遗传相似系数在0.66～0.91之间,在遗传相似系数0.72处,可划分为5大类群,供试种质并不完全按照地理来源进行分类.54份油梨种质有较高的遗传多样性,遗传信息丰富,ISSR标记对其多态性检测有效性高,适用于其遗传多样性分析.

本文对油梨资源圃内51份油梨种质资源果实的经济性状进行系统鉴定与评价,以探明资源圃内各油梨资源特性及有效性,筛选出具有优异特性经济性状的油梨资源,为油梨选育种及产业发展提供种源基础.结果 表明,根据所测得的油梨经济性状外观数量指标聚类,综合分析Ⅲ类(种质编号分别为是Dalin10#、Zaosu、lulla、ST0、Lincon、Dalin14#、Negra、Queen、Guiyan10、Zutanno)最具经济性状,单果重300～400g居多,可食率最高,其果肉厚度中上等,综合来看最具油梨外观品质经济性状优势.

以4个品种油梨为材料,分析其开花物候期的变异规律,了解油梨花器官特性.结果 表明,供试油梨品种的开花物候期存在差异,变异系数为14.63％～73.68％,开花期在2月下旬至4月上旬,花期25～35 d,以富尔特开花最早,哈斯开花次之,桂研5号和桂研10号开花最晚.供试油梨品种花器官特征也存在一定的差异,聚伞圆锥花序,顶生或居间,属于完全花,花瓣颜色为绿色、黄绿色,花柱直立,均有花粉和蜜腺;但在花序主轴长、花序长度、花序宽度、花柄长度、小花数、小花直径及花瓣长度方面存在差异.

Litchi (Litchi chinensis Sonn. cv. 'Feizixiao') has a high market value. However, its value declines during postharvest storage because its quality deteriorates, and its pericarp turns brown. Therefore, safe and effective ways of improving litchi quality and inhibiting postharvest browning are required. In this study, 5-aminolaevulinic acid (5-ALA) and thidiazuron (TDZ) were applied to litchi fruit before harvest to determine their relative effects on litchi colour and postharvest storage characteristics. The results showed that preharvest 5-ALA application significantly increased postharvest fruit weight, anthocyanins, total phenol, vitamin C and antioxidant activity relative to those in the untreated fruits. Compared with the control, TDZ significantly increased fruit weight but inhibited anthocyanin accumulation and did not significantly alter antioxidant activity. Both preharvest treatments significantly reduced the browning index, the relative leakage rate and polyphenol oxidase activity after 6 d of storage. A membership function analysis indicated that preharvest 5-ALA application was the most beneficial for postharvest storage whereas TDZ treatment was relatively less effective. Preharvest colour promotion was preferable for improving litchi quality and inhibiting postharvest browning.

以油梨(Persea americana)抗根腐病品种‘Duck7’的茎段为试验材料,WPM为基础培养基,采用Design-ExpertV8.0.6软件设计油梨不同快繁阶段的植物生长调节剂配比,通过观测相关指标,结合植物生长调节剂间互作效应,推测出不同生长阶段的最佳植物生长调节剂组合并进行验证.结果 表明:(1)油梨最佳不定芽诱导培养基为WPM+0.13 mg·L-1TDZ+1.72 mg·L-16-BA+0.1 mg·L-1NAA,经验证,该配方的不定芽诱导率达95％,比原设计组合最高诱导率高出1.67％;(2)油梨最佳不定芽增殖培养基为WPM+1.73 mg·L-16-BA+0.2 mg·L-1NAA,经验证,该配方的增殖系数达3.18,比原设计组合最高增殖系数高出0.03;(3)油梨最佳生根培养基为1/2MS+0.5mg·L-1 IBA+0.34 mg·L-1 NAA+1 g·L-1活性炭,经验证,该配方的生根率达66.67％,比原设计组合最高生根率高出5％.综上所述,本研究探索出了‘Duck7’油梨的离体快繁技术,可为油梨抗根腐病砧木的批量扩繁提供技术参考.

Using non-woven bag,white paper bag,kraft paper bag separately covered the'Pollock' avoca-dos after the second physiological drop,we measured regularly the changes of internal and external quality indexes such as fruit color parameters,fruit shape index,and the content of pericarp pigment,soluble sug-ar,soluble solids,Vc,fat,soluble protein.T he purpose is that studies on the effect of different bagging materials on the grow th and development process of avocado fruit in the appearance quality and internal quality.It aims to provide a theoretical basis for high quality cultivation of avocado.The results showed that:(1)the three kinds of bagging materials could significantly promote the grow th of avocado fruit. They significantly increased the single fruit weight of mature fruit,but there is not significant effect on the grow th and development and maturity on avocados.(2)Non-woven bags could significantly improve the fruit shape index of avocados,while the other two bagging materials did not.Although the kraft paper bag could significantly increase the brightness of fruit,but would make the pericarp turn yellow.White paper bags and non-woven bags could increase fruit brightness,but they were not significantly different from the control group.(3)Non-woven bags and paper bag processing could significantly improve carotenoids and chlorophyll in pericarp,soluble sugar,soluble solids,VC,fat and soluble protein contents in pulp of avo-cado.Kraft paper bag also could significantly improve soluble solids,soluble sugar,soluble protein and fat contents in pulp of avocado,w hile reducing the chlorophyll content in pericarp and Vc content in pulp,in-hibition of carotenoid synthesis and accumulation in pericarp.(4)All bagging materials could also change the avocado pericarp thickness.The kraft paper bags could significantly improve the pericarp thickness, while non-woven bags and white paper bags have reduced the pericarp thickness.All bags had no signifi-cant effect on pulp's density.(5)According to the comprehensive analysis of membership function meth-od,the results indicated that non-woven fabric bags are optimum bagging materials,and the white paper bags are the second.These results greatly enriched the suitable bagging materials can significantly promote the avocado's grow th and development,improving the appearance quality and internal quality of avocado fruit.In this experiment,the effect of non-woven bag bagging is the best.

本研究以皇帝蕉母株及抽生的吸芽为试验材料,用不同剂量的多效唑处理香蕉吸芽,观测香蕉吸芽及母株株高、茎粗、有效叶片数及吸芽死亡量等指标,利用隶属函数法对除芽效果进行综合评定,筛选多效唑除芽效果最佳的剂量.结果表明,各剂量的多效唑处理香蕉吸芽均不同程度的抑制其生长,其中以5 g和7 g剂量的多效唑除芽效果最佳,死亡率均为100％.同时,多效唑处理也能促进香蕉母株的生长,当剂量为5 g时,母株株高和茎粗增长率均达到最大,分别为3.24％、2.96％,比未经处理的吸芽增加了1.98％和1.88％.经隶属函数法分析,除芽效果强弱顺序为:5 g＞7 g＞3 g＞1 g＞CK1＞CK2,5 g多效唑处理的综合评价指数最高,为0.94,与对照相比不仅可高效的一次性除掉吸芽,也能加速香蕉母株株高和茎粗的生长.因此,在生产上可选取5 g多效唑作为香蕉除芽药剂进行推广应用.

The suckers from a mother plant of banana were used as the test material.On the basis of a single factor experiment,the experiment plan of the desuckering effect with mixed agents of potassium dihydrogen phosphate and paclobutrazol was designed using a Design-Expert 6.0 software.The desuckering effect of different mixture and the influence of the reagent on the banana mother plant growth was analyzed.Results of the interaction effect analysis and the best reagent proportion were predicted and verified in the field.Results showed among the 13 dose combinations of potassium dihydrogen phosphate and paclobutrazol in 1.5～8 g,the combination of 8 g potassium dihydrogen phosphate and 3.84 g paclobutrazol had the best effect on disbuding and promoting plant growth of banana.The mortality of banana sucker 3 days after was up to 100％.The treated suckers were wilted and rotten.The increasing rates of stem height and diameter 15 days after was up to 9.76％ and 6.94％.Therefore,potassium dihydrogen phosphate mixed with paclobutrazol in a ratio 2∶1 is recommended as an efficient,safe and economical desuckering agent.

本研究基于3S技术,全面、系统、精细地规划了贵州油梨种植区范围及面积,旨在为国内油梨产业健康、有序发展提供科学依据.本研究采用1995年至2014年贵州省主要气象站点的气象资料及海拔图、坡度图和土地利用图,结合油梨的生物学特性及其对气候环境的要求,分析影响贵州油梨发展的关键时期和关键因子,建立经度、纬度、海拔、坡度等地理因子与关键因子关系模型,从而确定贵州油梨的最适种植地域及面积.贵州油梨种植适宜区总面积为1.090 244×105 hm2,共分布在贵州赤水市、习水县、兴义市、望谟县、黎平县、镇宁县、关岭县、安龙县、罗甸县、晴隆县、普安县、兴仁县、贞丰县、荔波县、紫云县、平塘县、册亨县共17个市(县).将油梨种植适宜区分为两种类型:优势区和一般区,其中种植优势区的面积为9.560 127×104 hm2,占87.69％,总体分布在南盘江流域、北盘江流域及红水河流域范围内;一般种植区的面积为1.342 313×104 hm2,占12.31％,分布在赤水河流域、都柳江流域、漳江流域.将3S技术应用到农业布局区划中,可准确、高效的指导农作物的未来发展区域.本研究成果可为贵州油梨产业种植结构调整和发展布局提供科学依据.

This study investigated the desuckering effect of a 2:1 mixture of KH2PO4 (KDP) and paclobutrazol (PBZ) and its influence on banana mother plant growth, fruit yield, and quality. The mixed reagent was injected into suckers sprouting from 5-month-old banana (Musa paradisiaca AA) plants after removing the above-ground part of the suckers. Compared to control plants, treatment with the KDP/PBZ mixture significantly reduced superoxide dismutase, peroxidase, and catalase activities but increased malondialdehyde content at sucker growth points and in adjacent tissue after 1 d. There was evidence of damage to the cellular structure at sucker growth points after 2 d of treatment, with an increase in intercellular space as well as rupturing and death of most cells. All suckers died 3 d later, resulting in a mortality rate of up to 100%, and there was no subsequent regrowth of the dead suckers; indicating that a single application of the KDP/PBZ reagent is a viable desuckering practice. Relative to the control, the treatment of suckers also indirectly increased the height and stem diameter of mother plants, which was associated with increased fruit yield (yield per plant, weight per hand, weight per fruit, transverse and longitudinal diameters of fruit fingers) and enhanced nutritional quality of the fruits (edible fraction, soluble solid, titratable acidity, vitamin C, and moisture content). These results indicate that a 2:1 KDP/PBZ mixture can effectively remove banana suckers while improving fruit yield and the quality of the mother plant. The proposed desuckering practice can help to address challenges associated with banana production such as difficulties in desuckering and preventing sucker regrowth, minimizing fertilizer waste, and high costs.

This paper first identified the cold resistance of 38 varieties of avocado by determining the semi-lethal low temperature (LT 50 ) of the leaves using an electrical conductivity method in combination with a logistic function, and then analyzed the correlation between the LT 50 of 27 varieties and the capacitance measured 9 different parts of the leaves in vivo, to explore the relationship between the cold resistance of various avocado varieties and the capacitance of different parts of avocado leaves, so as to develop a new method for highly effective identification of cold resistance of living avocado varieties. The results showed that various avocado varieties’ LT 50 was significantly positively correlated with the capacitance of some parts of leaves, showing that the cold resistance of various avocado varieties was negatively correlated with the capacitance of various leaf parts. The results of mango variety trials conducted for comparison is coincident with the theoretical conclusion reached in the identification of the cold resistance of the avocado. So as to the study of the cold resistance of avocado and mango varieties, the capacitance of live mature leaves measured in the field can be used as a new method for the judgment of cold resistance. Highlight A new method for identification of avocado cold resistance through measuring the capacitance of different parts of leaves was developed. This method are simple, quick and efficient.