Bactrocera dorsalis preference for and performance on two mango varieties at three stages of ripeness

Most tropical fruit flies only lay into mature fruit, but a small number can also oviposit into unripe fruit. Little is known about the link between adult oviposition preference and offspring performance in such situations. In this study, we examine the influence of different ripening stages of two mango, Mangifera indica L. (Anacardiaceae), varieties on the preference and performance of the Oriental fruit fly, Bactrocera dorsalis (Hendel) (Diptera: Tephritidae), a fly known to be able to develop in unripe fruit . A series of laboratory-based choice and no-choice oviposition experiments and larval growth trials were carried out. The results demonstrated a general preference by B. dorsalis for mango variety Oakrong over variety Namdorkmai, but in most cases the single largest dependent variable influencing results was fruit ripening stage. Ripe and fully-ripe mangoes were most preferred for oviposition by B. dorsalis . In contrast, unripe mango was infrequently used by ovipositing females, particularly in choice trials. Consistent with the results of oviposition preference, ripe and fully-ripe mangoes were also best for offspring survival, with a higher percentage of larval survival to pupation and shorter development times in comparison to unripe mango. Changes in total soluble solids and pericarp toughness correlated with changing host use across the ripening stages. Regardless of the mango variety or ripeness stage, B. dorsalis had difficulty penetrating the pericarp of all fruits offered in experiments. Larval survival was also often poor in all experiments. We discuss the possibility that there may be differences in the ability of laboratory and wild flies to penetrate fruit for oviposition, or that in the field flies more regularly utilize natural fruit wounds as oviposition sites.     

与芒果子叶切段不定根形成相关基因的cDNA片段的克隆

在研究芒果子叶横切所形成的远轴面和近轴面的不定根形成时发现,只在近轴面形成不定根.该研究利用抑制性扣除杂交(suppres sive subtractivehybridization,SSH)方法,以子叶切段远轴切面作为参照样品,近轴切面作为检测样品,构建正向差异cDNA文库,分离与芒果子叶切段不定根形成相关基因的cDNA片段.经VirtualNorthern杂交分析,获得6个阳性克隆.序列分析和同源性比较结果表明这些cDNA片段均为首次报告,它们分别与转运蛋白、转录调控因子及酶基因的DNA序列同源.     

Variation in Anther Culture Response and Fertility of Backcrossed Hybrids between Indica and Japonica Rice (Oryza sativa)

This study was conducted to investigate the variations of fertility, callus induction and plant regeneration in backcrossed hybrids between a responsive japonica variety (Mankeumbyeo, recurrent parent) and a recalcitrant indica variety (Ranta Emas, donor parent) to anther culture. The mean spikelet fertility of inter-subspecific F₁ and BC₁F₁ hybrids was 33.5% and 67.2%, and the spikelet fertility of BC₁F₁ among backcrossed hybrids showed the most extensive variation (a low of 4.5% to a high of 90.6%). The mean fertility and distribution range in BC₅F₁ hybrids were almost the same as that of the japonica recurrent parent (94.6%). The mean callus induction of F₁ and BC₁F₁ hybrids was higher than that of donor parent, and the distribution range in BC₁F₁ hybrids varied from a low 0% to a high 18.7%. The mean callus induction and plant regeneration of BC₄F₁ hybrids was almost that of japonica recurrent parent, and there were no statistical differences between BC₄F₁ and BC₅F₁ hybrids. These results may help to accelerate the introgression of desirable traits from indica into japonica rice using anther culture of backcross hybrids as a breeding strategy.     

Functional groups of Sahelian trees in a semiarid agroforestry system of Senegal

Aims Addressing plant responses to water stress is critical to understand the structure of plant communities in water-limited environments and to forecast their resilience to future changes in climate. In a semiarid agroforestry system in the Sahelian savannah of Leona (Senegal), we selected nine common tree species and explored their stress-resistance mechanisms. These species represent a variety of life forms and are of high regional socio-economic importance. We hypothesized that different species would show different suites of traits to cope with water stress and expected to identify functional groups differing in strategies to withstand water shortage.Methods Along a dry and a wet season, we monitored four traits reflecting above- and below-ground strategies of resource acquisition such as predawn leaf water potential (ψ pd), specific leaf area (SLA), leaf thickness and leaf area index (LAI). We also measured two morphological traits: trunk diameter and tree height. LAI and ψ pd were measured six times during the dry and rainy seasons, and the other traits were measured once.Important findings We identified two functional classes subdivided into two functional groups of each class. The first class included deciduous and semi-deciduous species that generally had large SLA, low leaf thickness and small-to-intermediate inter-seasonal variations in ψ pd. The second class included evergreen species of two functional groups that differ in SLA, leaf thickness and the magnitude of inter-seasonal variations of ψ pd throughout the year. The four functional groups identified in this study represent plant strategies differing in their response to changing environmental conditions.     

中国科学家绘制籼稻高质量参考基因组序列图谱

2005年多国合作的国际水稻(Oryza sativa)基因组测序项目绘制了粳稻(O.sativa subsp.japonica)品种日本晴的参考基因组序列。最近,中国科学家发布了2个籼稻(O.sativa subsp.indica)品种(明恢63和珍汕97)的高质量参考基因组序列,为籼稻的功能基因组学研究和分子育种应用提供了便利。     

Development of microsatellite markers for mango (Mangifera indica L.)

Microsatellite markers for mango (Mangifera indica L.) were developed using a genomic library enriched for (GA)_n and (GT)_n dinucleotide repeats. A subset of 41 positive clones was sequenced and primers were designed. Twenty‐eight primer pairs produced polymorphic amplification products for a diversity sample including 15 mango cultivars and two accessions from the related species Mangifera laurina and Mangifera applanata. Nineteen simple sequence repeat (SSR) loci with clear scorable patterns were chosen to study diversity in the mango germplasm bank of Guadalupe (FWI). The number of alleles ranged from three to 13 with observed levels of heterozygosity ranging from 0.059 to 0.857.     

印楝提取物的杀虫活性及其中四降三萜研究

从印楝（Azadirachta indica）种仁的提取物中分离得到10仆四降三萜化合物,能过波谱方法鉴定,它们分别是nimbin(1),deacetylnimbin(2),salannolide(3),azadirachtin(4),vepaol(5),isovepaol(6),3-tigloyl-azadirachtol(7),1-tigloyl-3-acetyl-azadirachtinin(8),3-tigloy-azadirachtinin(9),1-tigloy1-3-acetyl-11-hydrox-ymeliacarpinin(10)。此外,还得到β－谷甾醇、豆甾醇、胡萝卜甙和硬脂酸。含印楝素（azadirachtion)为0.5%的印楝提取物在稀释150－800倍时对小菜蛾和菜粉蝶的人较强的防治作用。     

水稻新种质明恢86及其系列组合的选育研究

通过选用籼粳交中间材料与籼型强恢材料杂交导入广亲和基因的育种方法,将粳稻基因渗入籼稻恢复系,育成的三系及二系新种质明恢86,具有广亲和性、恢复力强、恢复谱广、米质优、配合力好、抗稻瘟病、制种产量高等特点.明恢86与野败型、矮败型、K型败、印尼水田谷型、冈型败、D型败、两用不育系、新质源不育系(岳4A)等多个不育系配组,均表现出强优的杂种优势和优良的综合性状,其中汕优明86、福两优2186、Ⅱ优明86已先后通过福建省或三明市农作物品种审定委员会审定.目前,正在福建和全国南方稻区大面积推广应用.