Calcium-Boron Addition Promotes Pollen Germination and Fruit Set of Mango

Different concentrations of calcium and boron were investigated for their effects on pollen germination and fruit set in mango cv. Mahachanok grown for off-season production. A randomized complete block design utilizing five treatments (1.0, 2.0, 3.0, and 4.0 mL/L 40% calcium (Ca) and 0.3% boron (B) with water as a control) with six replicates per treatment was used. The solution was sprayed onto trees at three stages, i.e., bud swell, floral development (also termed the “asparagus” stage), and before flower opening. Foliar application of Ca-B at a concentration of 3.0 mL/L exerted a significant stimulatory effect on pollen germination and pollen tube growth (P ≤ 0.05). This concentration also increased inflorescence length and the number of hermaphroditic inflorescences, and enhanced fruit set of mango cv. Mahachanok (P ≤ 0.05). Foliar application of the Ca-B solution at a concentration of 3.0 mL/L, therefore, generated positive effects with the trees producing more fruit and having greater productivity.     

野生毛葡萄种质资源及利用研究进展

从资源收集、种质评价、遗传及现代生物技术研究、品种选育和种苗繁育等方面对野生毛葡萄进行系统综述,指出其在种质资源收集、选育种及栽培的应用研究不够,使得毛葡萄科研出现种质缺乏,创新不出优良种质,生产上使用不合适品种(系)种植, 以及病害严重、低产、不稳产、品质差和产期集中等问题,今后毛葡萄种质收集及创新目标应重点放在两性花、抗病、高糖、低酸、高产稳产等性状上.     

Selectivity matters: Rules of thumb for management of plate‐sized,sex‐changing fish in the live reef food fish trade

Effective management of fisheries depends on the selectivity of different fishing methods, control of fishing effort and the life history and mating system of the target species. For sex‐changing species, it is unclear how the truncation of age‐structure or selection of specific size or age classes (by fishing for specific markets) affects population dynamics. We specifically address the consequences of plate‐sized selectivity, whereby submature, “plate‐sized” fish are preferred in the live reef food fish trade. We use an age‐structured model to investigate the decline and recovery of populations fished with three different selectivity scenarios (asymptotic, dome‐shaped and plate‐sized) applied to two sexual systems (female‐first hermaphroditism and gonochorism). We parameterized our model with life‐history data from Brown‐marbled grouper (Epinephelus fuscoguttatus) and Napoleon fish (Cheilinus undulatus). “Plate‐sized” selectivity had the greatest negative effect on population trajectories, assuming accumulated fishing effort across ages was equal, while the relative effect of fishing on biomass was greatest with low natural mortality. Fishing such sex‐changing species before maturation decreased egg production (and the spawning potential ratio) in two ways: average individual size decreased and, assuming plasticity, females became males at a smaller size. Somatic growth rate affected biomass if selectivity was based on size at age because in slow growers, a smaller proportion of total biomass was vulnerable to fishing. We recommend fisheries avoid taking individuals near their maturation age, regardless of mating system, unless catch is tightly controlled. We also discuss the implications of fishing post‐settlement individuals on population dynamics and offer practical management recommendations.     

腹足纲繁殖生物学研究进展

腹足纲是动物中仅次于昆虫纲的第二大纲。随着分子生物学技术的发展,原来基于形态学特征建立的分类不断被修正,并由此导致一些分类单元的繁殖生物学习性重新调整。现代分子生物学的发展也为腹足纲性别决定机制和性别分化机制提供有力证据和支持。本研究基于最新的腹足纲分类,对该纲部分物种从繁殖生物学的进化、性别决定机制和性别分化进行阐述,以期为腹足纲物种资源保护与利用提供参考。