现代生物技术在香蕉种质资源的研究与应用

香蕉是重要的热带亚热带水果,本文综合相关文献资料,从香蕉的起源与分布和现代生物技术在香蕉种质资源的研究与应用等剖析香蕉种质资源研究和应用的现状。对香蕉起源与分布的认识是香蕉种质资源研究的基础,目前多数学者都承认香蕉起源东南亚,对演化路线却存在许多争议,现代分子生物技术为解决这一问题提供了机会;分子标记技术成为香蕉遗传多样性研究的重要工具,可以很方便地进行香蕉分类、亲缘关系及演化做较为精确的研究,甚至辅助育种的应用;组织培养、细胞悬浮体系和原生质体培养技术的不断成熟,促进香蕉种质创新的发展,使香蕉突变育种和转基因育种成为可能。     

Cytoplasmic genetic diversity in bananas and plantains

Summary Concerns over yield declines in bananas and plantains due to the spread of Black Sigatoka disease in Musa have drawn attention to the collection of Musa germplasm and its use in conventional and biotechnological improvement programs. This report demonstrates the use of chloroplast DNA (cpDNA) restriction fragment length polymorphisms (RFLPs) for differentiating cytoplasms of various Musa clones. DNA was extracted from lyophilized leaf blade tissue and digested with either Eco R1, Hind III, Bam H1 or Pst I. Southern blots onto nylon membranes were probed with radioactively labeled heterologous orchid and lettuce cpDNA fragments. Among the 14 Musa clones examined, a single balbisiana and four acuminata-type cytoplasms were differentiated. The ability to distinguish between cytoplasms and to place plants within a cytoplasmic grouping demonstrates the usefulness of RFLP technology in evaluating diversity and determining the ancestry of Musa clones.     

Molecular breeding in the genus Musa: a strong case for STMS marker technology

Musa species are among the tallest monocotyledons and include major food-producing species. The principal cultivars, derived from two major species Musa acuminata (‘A’ genome) and Musa balbisiana (‘B’ genome), are polyploid hybrids (mainly AAA, AAB and ABB triploids), medium to highly sterile, parthenocarpic and clonally propagated. Bananas and plantains are crops to which molecular breeding is expected to have a positive impact. In order to better understand banana genetics, more knowledge has to be accumulated about the complex genome structure of hybrids and cultivars. Therefore, the aim of our work is to develop molecular markers that are codominant, reliable, universal, highly polymorphic and that are applicable to collaborative Musa germplasm genotyping and mapping. Two size-selected genomic libraries have been screened for the presence of simple sequence repeats (SSR). Our data demonstrate that SSR are readily applicable to the study of Musa genetics. Our comprehensive analyses of a significant number of banana sequence tagged microsatellite sites (STMS) will add to our knowledge on the structure and phylogeny of genomes of the Musa species, and suggest that microsatellites be used as anchor markers for a banana genetic core map. Additional markers, such as e.g. CAPS have also been tested in order to increase the detection of polymorphisms exceeding that revealed by STMS technology. The utility of PCR-derived markers for collaborative genetic analyses of the banana genome, and the transferability of 'streamlined’ laboratory techniques and data analysis to Developing Countries are discussed. This revised version was published online in July 2006 with corrections to the Cover Date.     

Hand pulling of Striga hermonthica in pearl millet∗

Abstract

Before 1960, Panama disease (fusarium wilt) was the most important disease in the banana export trades. Although the importance of Panama disease decreased after the Cavendish cultivars replaced Gros Michel, recent outbreaks have renewed interest in this problem. Race 4 affects cultivars of the Cavendish subgroup in the subtropics, as well as race 1 and race 2 suscepts. It has caused concern in the tropically based export trades which depend almost entirely on the Cavendish clones. Attention is also drawn to affected non‐exported bananas which are important cash crops or staple foods. Although they are not as well documented as those on the Cavendish subgroup, epidemics of the disease on non‐exported bananas are far more important.     

Influence of Potassium Fertilizer on Yield of Plantain Intercropped with Cassava on an Oxic Paleustalf in Southwestern Nigeria

Abstract

There is very little literature on the influence of plantain–cassava intercropped on this soil type. Therefore, an experiment was conducted in 1993 and 1995 cropping seasons on the influence of potassium (K) fertilizer on the yield of the two crops on a soil classified as Oxic paleustalf (or Ferric Luvisol) in the rain forest agroecological zone of Nigeria. Four rates of K fertilizer (120, 240, 360, and 480 kg K ha^?1) and control were evaluated on the yield and yield components of these two crops in sole and intercropping. The experimental design was a randomized complete block (RCBD) replicated four times. Results showed that the soil is acidic and the exchangeable cations contents were suboptimal when compared with the optimum required for a sustained cultivation of plantain. Furthermore, the plantain–cassava intercropped yields responded significantly (p<0.05) to fertilizer applied in terms of the yield and yield components of both crops in sole and intercropping. Highest bunch weight of plantain and tuber yield of cassava was recorded at 360 and 240 kg K ha^?1 (taking the mean of both years). Potassium fertilizer after this point resulted in lower yields of both crops when intercropped.     

哈茨木霉C184菌株对喀麦隆香蕉及大蕉根部病原菌的体外拮抗作用(英文)

体外测定了新近分离自喀麦隆香蕉及大蕉田间的哈茨木霉(Trichoderma harzianum)菌株C 184对香蕉和大蕉根部病原菌柱枝孢(Cylindrocladium pteridis)及茄镰孢(Fusarium solani),尖镰孢(Fusarium oxysporum)和曲霉 (Aspergillus sp.) 的拮抗作用. 在对峙培养中上述病原菌菌丝生长均受到明显抑制;在赛咯酚分层培养中木霉菌株对上述病原菌菌丝生长的抑制率为67%～88%;木霉菌株培养滤液对上述病原菌菌丝生长的抑制率为52%～87% .电镜下观察到木霉菌株对柱枝孢及镰孢霉的寄生过程,认为这可能是主要拮抗机制之一; 此外木霉菌株在液体培养中产生的抗生素及细胞壁降解酶也可能是抑制病原菌菌丝生长的主要原因.     

车前草穗枯病研究Ⅲ杀菌剂室内毒力测定

车前草穂枯病是江西吉安车前草产区发生最严重的一种真菌病害。本文采用菌丝生长速率法测定了6种杀菌剂对车前草穂枯病菌的毒力,结果表明菌毒神丹的毒力最强,EC50值为3.2921μg/mL;多菌灵的毒力最弱,EC50值为8 316.0393μg/mL;其他4种药剂已蒜素、奥普安、代森锰锌和菌毒克的毒力介于其间,EC50值依次为7.8253μg/mL,32.9139μg/mL、140.7006μg/mL和400.4089μl/mL。