广西香蕉种植户技术需求意愿及影响因素分析

以广西12个县(区)的257户香蕉种植户的实地调查资料为依据,通过对广西香蕉种植户技术需求优先序的分析,运用二元Logistic模型实证分析其技术需求的影响因素.结果表明,广西香蕉种植户最需要的4种技术依次为病虫害防治技术、高品质管理技术、施肥技术、新品种技术;而生产决策者特征、家庭因素、组织因素、风险因素、技术信息服务等也不同程度地影响着广西香蕉种植户技术的需求行为.     

液相色谱法测定香蕉中赤霉素残留

建立香蕉中赤霉素残留量的测定方法。样品经甲醇提取，使用石油醚进行脱色，经C18固相萃取小柱净化后，使用高效液相色谱法(紫外检测器)进行测定。方法检出限为0.1 mg/kg，在0.50～10.0 mg/kg添加水平，回收率为86% ～105%，相对标准偏差为2.0%～4.8%。     

云南香蕉业现状、优势和发展思路

简述我国香蕉的产销形势,分析云南香蕉业的现状和存在问题,提出了云南香蕉业发展的思路。     

Selection parameters for resistance to Fusarium oxysporum f. sp. cubense race 1 and race 4 on diploid banana (Musa acuminata Colla)

Summary Shoot tip cultures from banana clones susceptible and resistant to Fusarium oxysporum f. sp. cubense (FOC) race 1 and race 4 were grown in vitro in the presence of different concentrations of fusaric acid and fungal crude filtrates or inoculated with a conidial suspension of FOC to assess correlation between in vivo and in vitro behaviour. Explants were susceptible to both filtrate and fusaric acid irrespective to their known field resistance/susceptibility response. No clear linkage between in vivo and in vitro behaviour was observed and our results suggest that the use of crude filtrate or non-host specific toxin (fusaric acid) in a screening programme for selecting a novel resistant genotype of Musa to FOC is not feasible. When peroxidase activity was used as a parameter to discriminate between sesceptibility and tolerance, results were in good agreement with field response of host plant to pathogens. Early enzymatic activity increased in the incompatible host-pathogen interaction but not in the compatible interaction.Abbreviations IBA Indolebutyric acid - 2iP 6-dimethylallylamino-purine - VCG Vegetative Compatibility Group - FOC Fusarium oxysporum f. sp. cubense - IEF isoelectrofocusing     

RFLP characterization of Indian Musa germplasm for clonal identification and classification

Summary Nineteen single-copy clones isolated from a PstI genomic library (cv. Maiden Plantain), and eight Vigna chloroplast DNA clones were used to probe total genomic DNA digests of 57 genotypes of Musa from India. The 19 genomic clones detected a total of 107 polymorphisms among the 57 genotypes. Principal coordinates and phenetic analyses of these data placed cultivars and species into distinct groups that were in general agreement with a previously published RAPD-based classification of these same plant materials. The 107 polymorphisms were sufficient to differentiate each clone from every other clone. Heterologous Vigna chloroplast DNA probes were used to characterize the cytoplasm of Musa cultivars and species. PCO analysis of these RFLPs were detected both within and between the generally recognized genome groups, indicating multiple hybridization pathways in the origin of hybrid clones. Data presented demonstrate that RFLPs are sufficiently abundant to classify Musa germplasm and that genetic relationships among Musa cultivars, based upon RFLP data, are in general agreement with relationships determined by analysis of morphology and RAPDs.     

高产香蕉平衡施肥技术研究

在肥力较高的老蕉园进行平衡施肥技术研究。结果表明:当第一造蕉氮肥用量达到1000kg/hm2以上及氮钾肥施肥比例N K2O为1 1 15时,香蕉抽蕾提前,蕉果农艺性状及品质较好,产量达到52 5t/hm2的高产水平,获得较好的经济效益;随着施钾比例的增加,香蕉的营养生长受到一定的限制,农艺性状及品质均变差,产量及经济效益均有所下降。在土壤Mg/K=1 37的情况下增施镁肥,香蕉的营养生长受到一定影响,蕉果的农艺性状下降,但固形物与可溶糖含量提高,产量及经济效益明显降低;施用硫肥对香蕉的生长及产量影响不大,但由于增加了肥料成本而使经济效益有所下降。     

Effects of an arbuscular mycorrhizal fungus and two plant-parasitic nematodes on<Emphasis Type="Italic"> Musa</Emphasis> genotypes differing in root morphology

In this study, the effect of an arbuscular mycorrhizal fungus (AMF) and two migratory endoparasitic nematodes on Musa plant growth, including the root system, were examined. In addition, the AMF-nematode interaction was studied. Seven Musa genotypes with different root systems were selected. Based on their relative mycorrhizal dependency, two genotypes (Calcutta 4 and Obino l'Ewai) were selected for AMF-nematode interaction studies. The experiments were performed under greenhouse conditions. Mycorrhization with Glomus mosseae resulted in a significantly better plant growth even in the presence of nematodes. The effect of AMF on the root system was genotype-dependent and seemed to be related to the relative mycorrhizal dependency of the genotype. The nematodes also affected the root system, decreasing branching. Nematode population densities were significantly reduced in the presence of AMF, except for Pratylenchus coffeae in Obino l'Ewai. In the root system, it appeared that the decreased branching caused by the nematodes was counterbalanced by the increased branching caused by the AMF.     

甜菜碱和壳聚糖对提高香蕉幼苗抗寒性的协同效应

研究甜菜碱和壳聚糖混合处理对香蕉幼苗抗寒性的影响,结果表明,甜菜碱和壳聚糖对提高香蕉幼苗抗寒性具有正向协同效应,主要是通过协同提高细胞保护酶SOD活性、降低叶片细胞的膜脂过氧化程度、减少过氧化产物MDA的积累、增加组织水中束缚水的比例、提高可溶性蛋白含量、降低质膜透性等来增强香蕉幼苗的抗寒性.     

香蕉果实expansin cDNA克隆及序列分析

提取成熟香蕉果肉的RNA并分离mRNA，以mRNA反转录合成cDNA，以该cDNA为模板，设计expansin的简并引物，进行RT-PCR(退火温度为50℃)，得到的扩增产物纯化后与pGEM-T-Easy载体连接，转化大肠杆菌，任意挑选2个阳性克隆，进行序列分析，结果得到2个序列相同的expansin的cDNA基因片段，命名为MA-Exp3(以示与已登录的香蕉MA-Expl和MA-Exp2的区别)，MA-Exp3中存在expansin基因的保守区域，即8个半胱氨酸残基和3个色氨酸残基，它编码177个氨基酸，与MA-Exp1的核苷酸同源性为74．2％，氨基酸同源性为86．4％。