小果野蕉(Musa acuminate Colla)花粉母细胞减数分裂过程异常的细胞学观察

香蕉是重要的热带水果,由于雄性不育、单性结实等原因导致其杂交育种困难。小果野蕉(Musaacuminate Colla)是现代香蕉栽培种的祖先之一,在理论研究和应用中有非常重要的地位。前期研究发现小果野蕉存在部分可育花粉,但导致花粉活力下降的原因未知。为了探求导致小果野蕉花粉活力降低的细胞学原因,本研究通过亚历山大红染色法对小果野蕉花粉活力进行检测,通过卡宝品红染色对小果野蕉花粉母细胞减数分裂阶段和小孢子发育阶段进行观察。结果表明:小果野蕉花粉活力为84.33%;小孢子发育阶段未见明显异常;正常四分体比例为81.3%;花粉母细胞减数分裂过程终变期、中期Ⅰ、后期Ⅰ、中期Ⅱ、后期Ⅱ均存在异常,比例分别为8.8%、8.5%、7.6%、10.6%、12.1%。因此,可能是部分花粉母细胞减数分裂异常导致小果野蕉花粉活力的降低。

Prevalence and Spatial Distribution of Badnavirus in the Banana (Musa spp) Major Growing Areas in Burkina Faso

Banana streak virus (BSV) and Sugarcane bacilliform virus (SCBV) are two badnaviruses commonly found in all banana growing areas of the world. It is a threat to the production and improvement of Musa germplasm. In Burkina Faso, the presence of badnaviruses was reported in banana producing regions. The objective of this study was to determine the prevalence of BSV and SCBV in banana production areas of Burkina Faso. A survey followed by a symptomatologic study was conducted in banana plantations in 27 localities of the nine main banana producing regions from July to October 2018 and September to December 2020. In all, 251 leaf samples were collected and analysed for BSV and SCBV infection by Indirect Antigen Coated Plate Assay-ELISA followed by amplification of the RT/RNase H region using Polymerase chain reaction with Badna FP/RP and SCBV F/R primers, respectively. A variety of symptoms were observed on almost all plant organs which were revealed due to BSV by symptomatologic study. The results of serological and molecular diagnosis revealed a high overall prevalence of BSV in 80.48% of the samples tested. BSV was distributed in seven survey regions out of nine with prevalence ranging from 10% to 100% in North, Centre, Centre West, Hauts Bassins, Cascades, Centre East and Boucle of Mouhoun regions. Very low prevalence was recorded for SCBV in Cascades and East Centre region with 4.35 and 12.5%, respectively. Species detection using specific primers to each species revealed three main species: Banana streak Obino l’ewaï virus (BSOLV), Goldfinger virus (BSGFV) and Imové virus (BSIMV) in the samples tested, respectively in the proportions of 23%, 8% and 0.8%. Co-infection between BSV species was also detected.

Formulation and evaluation of semisolid jelly produced by Musa acuminata Colla(AAA Group) peels

Objective:To study the jelly formulation produced by Musa acuminata Colla(AAA Group) peels and evaluate its antioxidant properties which are related to the product quality.Methods:The formulations of peel jelly were established under two-level full factorial designs within two blocks and one center point.Regarding response optimizer,the amount of sugar and citric acid was obtained;hence,the peel jellies were produced.The evaluation of antioxidant properties was conducted by using total phenolic content(TPC)assay and 1,1 diphenyl-2-picrylhydrazyl(DPPH) free radical assay.Results:The TPC of peel powder varied from 91.8 to 602.26 mg gallic acid equivalents/100 g dry weight,and 5%-7% peel jellies had phenolic content ranging from 29.38 to 48.31 mg gallic acid equivalents/100 g dry weight.The results of DPPH test indicated that at 10 mg/mL,the peel powder showed 89% DPPH inhibition,while 7% peel jelly prominently exhibited 84% DPPH inhibition.The correlation between DPPH IC50 value and TPC of peel powder as well as peel jelly was quite reasonably high with correlation coefficient ranging from 0.843 7 to 0.995.Conclusions:TPC can be used as an indicator in assessing the antioxidant activity of fruits and vegetables.The present investigation reveals that TPC is mainly responsible for DPPH free radical scavenging capacity.

香蕉中啶氧菌酯残留行为和膳食风险评估

香蕉生产中普遍使用啶氧菌酯,这可能对消费者健康造成潜在风险。为了评估膳食风险,我们拟研究香蕉中啶氧菌酯残留行为,在海南和云南两地分别开展香蕉中啶氧菌酯消解动态和最终残留试验,于施药后不同时间采样检测样品中啶氧菌酯残留,并计算膳食风险商。结果表明,在添加浓度0.02~1.0 mg/kg范围内,香蕉中啶氧菌酯的平均回收率为101.4%~109.2%,相对标准偏差为2.1%~4.0%,最小检出量为0.01 ng,最低检出浓度为0.02 mg/kg。香蕉中啶氧菌酯降解符合一级动力学方程,降解半衰期为8.7~13.8 d,最终残留量的最大值为0.045 mg/kg,施药60 d后香蕉中啶氧菌酯降解率大于99.62%。我国普通成人啶氧菌酯的估算每日摄入量估计为0.35 mg,风险商(RQ)为0.06,远远小于1。说明在该试验条件下,香蕉中啶氧菌酯的残留水平不会对普通成人造成膳食风险。

香蕉AP2/ERFs超家族的重新鉴定及在果实采后成熟过程中的差异表达特性

【目的】在全基因组水平上重新鉴定香蕉A基因组中的AP2/ERF家族成员,研究其在香蕉果实采后成熟过程中的差异表达特性,明确可能参与香蕉果实成熟调控的关键基因。【方法】对香蕉A基因组中AP2/ERF家族成员进行系统进化、结构特征、蛋白质特性、保守结构域分析和两大类主栽品种巴西蕉(AAA)和粉蕉(ABB)果实采后成熟不同阶段的转录组分析。【结果】发现AP2/ERFs家族共有317个家族成员,分为AP2(49个)、ERF(253)和RAV(15)三个亚家族,他们不均匀地分布在染色体上。根据保守结构域和基因结构特征,ERF又分为a、b、c、d、e、f、h、i、j和k共10个亚类。转录组分析结果表明,在巴西蕉果实采后成熟过程中差异表达的AP2/ERFs家族成员有77个,其中高水平表达的有MaERF15、36、42和AP2-28。在粉蕉果实采后成熟过程中差异表达的AP2/ERFs家族成员有74个,其中高水平表达的有MaERF42和AP2-28。同时在巴西蕉和粉蕉果实成熟过程中差异表达的基因有57个,其中高水平表达的基因有MaERF15、42和AP2-28,只在巴西蕉果实中特异表达的有20个,只在粉蕉中特异表达的有17个。【结论】重新鉴定了香蕉AP2/ERFs超家族成员及其在果实后熟过程中的差异表达特性,为系统深入解析香蕉AP2/ERF基因功能奠定了基础,对为调控香蕉果实成熟提供靶标基因具有一定的理论意义。

闽江流域野生蕉(Musa itinerans)遗传多样性和遗传结构的ISSR分析

采用ISSR分子标记技术对福建省闽江流域10个野生蕉自然居群的遗传多样性和遗传结构进行分析,结果显示:12条ISSR引物共检测出117个条带,105个多态性条带,多态性百分率为89.7%;野生蕉Nei遗传多样性指数为0.244,Shannon's信息指数为0.381,其中三明野生蕉遗传多样性水平最高,且不同自然居群间遗传多样性指数之间具有显著性差异;总遗传变异系数为0.589,基因流为0.349,居群间的遗传分化程度高于居群内;基于遗传距离的聚类结果与模型聚类结果均聚为3大类,分别为沙溪支流的三明野生蕉类群、闽江上游及附近支流的南平野生蕉类群和闽江下游的福州野生蕉类群。研究认为,闽江流域野生蕉资源丰富的遗传多样性主要来源于自然居群间生境异质化所引起的高频率遗传变异,且三明野生蕉类群的遗传多样性和遗传分化程度最高,可能是福建野生蕉的起源中心,也是野生蕉资源开发和利用的最主要群落。此外,水流是闽江流域野生蕉遗传迁移最关键的自然主导因素。

影响体胚发生途径香蕉(Musa spp.,AAB Group)植株再生的因素

香蕉品种‘Agbagaba’和‘Orishele’的胚性细胞悬浮系(ECS)在液体培养基中分别预培养1和2周后,将其接种在RD1和M3培养基上,于光照或黑暗条件下进行体胚的再生。从沉积细胞体积(SCV) 为1 mL(1 mL SCV)的ECS获得的再生体胚数量因预培养时间、再生培养基的种类及培养条件的不同而异。植株的再生率及从1 mL SCV的ECS获得的再生植株数量也受上述体胚再生条件的间接影响。

福州野生蕉(Musa spp.,AA Group)的发现及其分类学地位的初步确定

本文首次报道了福建省福州野生蕉(Musa spp.,‘AB’Group)的发现、分布、基本生物学特性;同时,根据Simmonds和Shepherd的分类方法,确认福州野生蕉属于AA类群,并初步分析了福州野生蕉的利用价值。

福州旗山野生蕉(Musa spp.,AB Group)试管苗Mn-SOD基因克隆及生物信息学分析

以旗山野生蕉(Musa spp.,AB group)试管苗幼嫩叶片为材料,利用RT-PCR结合RACE技术克隆获得野生蕉试管苗Mn-SOD基因c DNA序列。结果表明:旗山野生蕉Mn-SOD的c DNA全长序列共831 bp,其中5′UTR为137 bp,3′UTR为151 bp,3′端含有17个poly(A)尾。开放阅读框(ORF)共有543个碱基组成,编码181个氨基酸。蛋白理化性质预测结果显示:Mn-SOD蛋白分子量为20 108.8 u,等电点7.92,属于碱性蛋白。

福州宦溪野生蕉(Musa spp.,AB group)2个PSAG成员的克隆及生物信息学分析

植物光系统Ⅰ反应中心亚基Ⅴ(photosystemⅠreaction center subunitⅤ,简称PSAG或PSⅠ-G)是光合系统Ⅰ的主要组件,具有维持PSⅠ复合体稳定性的重要作用,并与抗盐密切相关。本研究以福州宦溪野生蕉(Musa spp.AB group)叶片为材料,采用同源克隆的方法 ,首次分离到PSAG基因的2个成员:PSAG1、PSAG2(GenBank登录号分别为JX317082、JX317083),分别为800、827 bp,分别编码150、160个氨基酸;PSAG1、PSAG2的基因组序列分析表明2个成员均没有内含子。生物信息学分析表明:PSAG1、PSAG2具有PSⅠ的Ⅹ亚基超家族(photosystemⅠreaction center subunitⅩpsaK)保守结构域,是不具有信号肽的跨膜蛋白,具有亲水性;PSAG1、PSAG2均有4个位点发生磷酸化。宦溪野生蕉PSAG在进化过程中形成了特殊的结构特征,即PSAG1和PSAG2没有内含子,并且在不同物种间保守区具有高度的一致性,为保持PSAG功能的稳定性提供了重要保证。

Musa chunii Hkkinen,a new species (Musaceae) from Yunnan,China and taxonomic identity of Musa rubra

The center of diversity of the genus Musa （Musaceae） is in Southeast Asia, a region not studied in detail and where new species and varieties continue to be reported. A new wild banana species, M. chunii Hakkinen from Yunnan, China is described and illustrated based on observed morphological characteristics in the field. This extremely rare new species was only found in Tongbiguan Nature Reserve, Dehong District, West Yunnan. A key to M. chunii and related taxa is provided. In addition, critical notes regarding M. rubra Kurz identity are given.

A taxonomic revision of Musa aurantiaca (Musaceae) in Southeast Asia

Since the initial description, the name Musa aurantiaca Baker (1893) has been unclear to most botanists. The aim of this study is to settle its true identity and to update the description. The plant is distributed in the regions of Upper Assam and Arunachal Pradesh, India, Northern Myanmar and Tibet, China where it occurs commonly but it is not mentioned in Chinese literature at all. In this paper, the authors also review the description and the literature history of M. aurantiaca from 1893 to the present. Musa aurantiaca Baker is typified here.

Protection of ultrastructure in chilling-stressed banana leaves by salicylic acid

Objective:Chilling tolerance of salicylic acid(SA) in banana seedlings(Musa acuminata cv.,Williams 8818) was investigated by changes in ultrastructure in this study.Methods:Light and electron microscope observation.Results:Pretreatment with 0.5 mmol/L SA under normal growth conditions(30/22 °C) by foliar spray and root irrigation resulted in many changes in ultrastructure of banana cells,such as cells separation from palisade parenchymas,the appearance of crevices in cell walls,the swelling of grana and stromal thylakoids,and a reduction in the number of starch granules.These results implied that SA treatment at 30/22 °C could be a type of stress.During 3 d of exposure to 7 °C chilling stress under low light,however,cell ultrastructure of SA-pretreated banana seedlings showed less deterioration than those of control seedlings(distilled water-pretreated).Conclusion:SA could provide some protection for cell structure of chilling-stressed banana seedling.

Characterization of Neopestalotiopsis clavispora , A New Etiological Agent of Leaf Spot Isolated from Banana

[Objectives]The study was to confirm the etiological agent of leaf spot on banana in Yunnan Province of China.[Methods]Fungus isolates were isolated from the diseased tissues,and cultured to observe the morphological characteristics of colony and spore.Furthermore,phylogenetic analyses and pathogenicity test were also conducted to confirm the pathogen.[Results]The fungus isolated from the diseased tissues was identified as Neopestalotiopsis clavispora.[Conclusions]N.clavispora is a new pathogen causing leaf spot of banana.This research provides the first description of N.clavispora as a causal agent on banana in China,and adds new insights related to the host range of N.clavispora.

Taxonomic history and identity of Musa dasycarpa,M.velutina and M.assamica (Musaceae) in Southeast Asia

Since the initial description, the name Musa dasycarpa Kurz (1867) has been unclear to most botanists. It has usually been synonymized with M. velutina H. Wendl. & Drude (1875). However, although the original diagnosis was very short, 'fruits hairy', it is adequate. Thus, according to Vienna Codes, M. dasycarpa Kurz has priority over M. velutina H. Wendl. & Drude. The aim of this study is to settle the true identity and to update the description of M. dasycarpa Kurz. For that purpose the names M. dasycarpa and M. velutina are typified. In addi-tion, critical notes regarding M. assamica Bull. are given; it is neotypified here, and considered as conspecific with M. sanguinea Hook. f.

Can Changes in Soil Properties in Organic Banana Production Suppress Fusarium Wilt?

Organic agriculture promotes disease suppression through healthy soils by increasing biological activity and diversity through the application of organic fertilizers and increasing organic inputs. Fusarium wilt of bananas (Fusarium oxysporum f. sp. Fcubense) (Foc), also known as Panama disease, has been a devastating disease throughout the world. So far, no fungicides or cultural measures have been found that control Foc sufficiently. The aim of this research was to assess whether organic-based farming systems were more resilient than inorganic farming systems to soil borne diseases, in particular Fusarium wilts. A survey was conducted comparing five organic and five conventional banana plantations at paired sites in north Queensland, Australia. Soil samples were collected and analysed for chemical, physical and biological soil health indicators. Disease development of F. oxysporum f. sp. lycopersici in tomatoes and Foc in bananas were studied in pot trials to pursue clues for identifying Fusarium suppressive soil traits. Organic soils from the survey showed higher microbial activity and lower disease symptom expression (both with tomatoes and bananas) than conventional soils. In the survey, nematode diversity and soil sulphate content were recurring indicators in all experiments showing close correlations to pathogen growth, disease expression and plant health. Organic soils were lower in plant-parasitic nematodes and sulphate sulphur levels and higher in nematode diversity, labile soil C and microbial indicators. Soil conduciveness or suppression of Foc appeared to be largely governed by competition for carbon. Measurement of soil microbial enzyme activity, nematode community structure and diversity and possibly sulphate sulphur seem to provide a relatively reliable indicator for general disease suppression. Differences between organic and conventional agriculture cannot be related to single management practices, but may be linked to synergies among system components.

Galactagogue effects of Musa x paradisiaca flower extract on lactating rats

Objective:To investigate the potential of Musa x paradisiaca(M.x paradisiaca)flower extracts in promoting milk production of lactating rats and its effects on growth of the suckling pups. Methods:Galactagogue activity was evaluated in terms of quantity of milk produced from the rats treated with petroleum ether,ethanol or water extracts of the flower.Lactating rats(n=5) of Spraque Dawley with six pups each were administered with the extracts in the amount of 500 mg/kg body weight,while the control rats were given an equivalent amount of distilled water.The rats were daily administered via oral feeding starting from Day 5 until Day 14 and the performance of milk production was measured along the experimental period by weight-suckle-weight method. Results were statistically analyzed using SPSS by means of ANOVA at 0.05 and was expressed as their mean±standard deviation.The rates of pups’ growth were measured as the weight gain along the experimental period.Results:The rats treated with aqueous extract produced higher milk than control and ethanol groups.Aqueous extract was identified to increase milk production by 25%,while petroleum ether extract by 18%.The mean of yields produced by the rats during suckling period for aqueous,petroleum ether,ethanol and control were 4.62±2.45,4.37±1.93,3.65±1.89 and 3.69±1.79,respectively.Growth rates of pups for the rats treated with control,aqueous, ethanol extract and petroleum ether were(1.85±0.49),(1.78±0.56),(1.65±0.46)and(1.56±0.42) g/pup, respectively.Conclusions:The present study reveals the potential of M.x paradisiaca flower to enhance milk production of nursing mothers which could be exploited for commercialization of the isolated extract.

BanSatDB, a whole-genome-based database of putative and experimentally validated microsatellite markers of three Musa species

The genus Musa is one of three genera in the family Musaceae, which includes bananas and plantains, which are monocotyledonous plants. Bananas have valuable nutritional content of vitamin C, B6, minerals, and dietary fiber and are a rich food energy source, given that carbohydrates account for 22%–32% of fruit weight. Molecular markers are valuable for crop improvement and population genetics studies. The availability of whole-genome sequence and in silico approaches has revolutionized bulk marker discovery. We describe an online web genomic resource, BanSatDB(http://webtom.cabgrid.res.in/bansatdb/) having the highest number(>341,000) of putative STR markers from Musa genera so far, represented by three species: M. acuminata(110,000), M. balbisiana(107,000), and M. itinerans(124,000)from 11 chromosomes of each species. BanSatDB has also been populated with 580 validated STR markers from the published literature. It is based on a three-tier architecture using MySQL, PHP and Apache. The markers can be retrieved by use of multiple search parameters including chromosome number(s), microsatellite types(simple or compound),repeat nucleotides(1–6), copy number, microsatellite length, pattern of repeat motif, and chromosome location. These markers can be used for Distinctness, Uniformity and Stability(DUS) tests of variety identification and for marker assisted selection(MAS) in variety improvement and management. These STRs have also proved to be helpful in classification of Musa germplasm to distinguish individual accessions and in the development of a standardized procedure for genotyping. These markers can also be used in gene discovery and QTL mapping. The database represents a source of markers for developing and implementing new approaches for molecular breeding, which are required to enhance banana productivity.

Morphological and Molecular Identification of Curvularia geniculata Associated with Leaf Spot Disease of Banana in China

[Objectives]The paper was to identify the causal agent of leaf spot of banana in Hainnan,China.[Methods]Fungus isolates were isolated from the diseased tissues,and morphological characteristics of colony and spore were observed.Furthermore,phylogenetic analyses and pathogenicity test were conducted to confirm the pathogen.[Results]The fungus isolates from the diseased tissues was identified as Curvularia geniculata.[Conclusions]C.geniculata is a new pathogen causing leaf spot of banana in Hainan,China.This finding will help to broaden the distribution and host range of C.geniculata,indicating that it poses potential damage to banana in China.

Assessing New Banana Genotypes for Relevant Traits: Implication for Variety Selection

Understanding the performance of new crop genotypes for traits of relevance is important in selecting potential cultivars to satisfy end-users. The objective of this study was to determine the performance of new banana genotypes for bunch mass (BMS) and BMS-related traits, resistance to black Sigatoka and sensory attributes. Eight cooking banana genotypes consisting of six new hybrid genotypes selected from advanced breeding trials and two control cultivars were evaluated in a randomized complete block design for three crop cycles at three locations in Uganda. Genotype, location, crop cycle and their interaction effects were significantly different for most traits assessed. The overall top two genotypes (“9058K-2” and “8099K-16”) combining high BMS, resistance to black Sigatoka and acceptable sensory attributes were identified. These genotypes are suggested as potential commercial cultivars for release to farmers in Uganda and/or other East African countries with similar environmental conditions to those where the genotypes were tested. It should be noted that high BMS/yield and resistance to diseases are not the only factors to consider when selecting banana genotypes that meet end-user needs. A combination of high BMS/yield, acceptable sensory attributes and resistance to diseases essentially influence the selection process of banana cultivars.