Realizing value of genetic resources of <Emphasis Type="Italic">Allium</Emphasis> in India

The genetic resources of Allium in India are potential source of genes for widening the crop genetic base. Despite their high economic value, limited number of germplasm accessions of wild species have been collected and conserved mainly due to difficult access to areas of occurrence. The present work mainly highlights information on species diversity distribution and utilization of wild Allium species to assess the value of Indian germplasm and prioritization for future collection and conservation programmes.     

新形势下北京高职院校招生宣传工作的应对型研究 ——基于北京农业职业学院2018级生源情况的调查

高等职业教育作为现代教育的重要组成部分,越来越受到社会的关注和认可,招生宣传工作很大程度上影响着高职院校生源的数量和质量,是一项需要全盘统筹、系统设计的工作。以北京农业职业学院的生源情况调查为例,分析北京高职院校当前招生工作生源情况、招收方式和面临的困境,通过数据解析,积极探讨新形势下如何做好招生宣传工作,提出有效的应对策略。     

Biotic strategies to increase plant availability of sewage sludge ash phosphorus

Sewage sludge incineration‐ash (FB‐I) represents a potential alternative phosphorus (P) fertiliser with a high concentration of P, although with relatively low crop availability. In this study, we investigated two P‐solubilisation approaches (acidification and P mobilisation by citrate) to enhance plant P uptake from the FB‐I ash in a pot study by using various biotic strategies: (1) a pre‐treatment of ash with a Penicillium bilaiae inoculum, (2) an isogenic line of wheat that excretes citrate from the root tip, (3) nitrogen (N) provided as combined with nitrification inhibitor dicyandiamide (DCD). All strategies were tested combined with each other and with different methods for ash application: (1) completely mixed within the top one third of soil in a pot, or (2) applied as distinct band at 10 cm depth. Triple super phosphate (TSP) at a rate of 15 mg P kg^?1 soil per pot was sufficient to support maximum shoot growth. Ash mixed into the first top third part of soil in the pot at a rate of 180 mg P kg^?1 soil (equivalent to 60 mg P kg^?1 soil throughout the pot) significantly increased the soil water‐extractable P and the subsequent shoot P uptake and shoot biomass for both wheat lines and microbial pre‐treatment to support maximum plant performance. Shoot P concentration in these treatments was further enhanced when the plants received and DCD, although not leading to a significant increase in shoot biomass. The citrate secretion by the root tips and pre‐inoculation with P. bilaiae of the ash did not influence plant growth. In conclusion, root‐zone soil acidification by nutrition is regarded as a promising strategy to improve the fertilising effect of such alternative P fertilisers originating from urban waste streams.     

新时代广西林业产业发展的问题及对策

指出了林业在广西的经济发展中发挥着非常重要的作用,新时代背景下,广西林业从基础的营造林产业逐步迈向综合的第三产业。为了让广西林业的发展紧跟时代的步伐,必须依靠科技进步,改变林业产业的结构,通过创新来促进广西林业产品结构的不断提升。基于此,论述了广西林业产业发展的现状,分析了存在的问题,提出了相应的对策建议,以期为广西林业产业的可持续建设提供参考。     

新时代国有林场党建工作的重要问题及发展对策

指出了随着我国经济水平的不断发展,人们对环境与资源的需求日益增加,由此出现的一系列环境问题又反过来限制了经济的发展。对国有林场来说,离不开员工的奉献与努力。在具体工作中,使党建工作和林场的生产经营相结合,与时俱进,积极创新,坚持党的为人民服务为宗旨,坚持党的群众路线和群众观点,以人为本,实事求是地践行党务工作,是壮大国有林场发展的重要步伐。主要论述了广西壮族自治区国有雅长林场的基本概况,分析了扶贫产业工作中存在的问题,并提出了相应的解决对策,以期为林场的可持续发展提供参考意见。     

植物功能性状及其叶经济谱对硬化地表的响应

为探究植物叶功能性状及其叶经济谱对城市硬化地表的响应,以北京市典型绿化树种白蜡(Fraxinus chinensis)、国槐(Sophora japonica)和栾树(Koelreuteria paniculata)为研究对象,选择城市环境中典型的3种地表类型:自然地表(CK)、透水硬化地表(T1)和不透水硬化地表(T2),测定其地表温度、土壤含水率及植物叶功能性状等指标。结果表明,硬化地表极显著地升高了城市地表温度(P 0. 01),且由大到小表现为T1、T2、CK,而极显著地降低了土壤含水率(P 0. 01),由大到小表现为CK、T2、T1;城市生态环境中,硬化地表对国槐和栾树的影响主要源于高温胁迫,而对白蜡的影响主要源于T2的干旱胁迫; 3个树种叶功能性状间表现出相对一致的生态对策,以适应城市环境的变化,叶绿素含量与比叶面积呈显著正相关(P 0. 05),且分别与叶干物质含量、叶组织密度呈极显著负相关(P 0. 01),叶干物质含量与叶组织密度呈极显著正相关(P 0. 01)。全球叶经济谱也存在于城市生态系统中,且总体上向快速投资收益型一端偏移,城市生态环境中植物通过减小气孔密度和比叶面积、缩小气孔面积、增加叶干物质含量和叶组织密度等策略,来适应城市生态系统中的高温、干旱等特殊生境。因此,在城市绿化植物的选择及配置上,建议根据其生态权衡规律,选择耐高温、耐旱的树种,同时通过增加降温、灌溉,减少生长季修枝等措施来降低不利影响。     

Predation effects on matrotrophy,superfetation and other life history traits in Phalloceros harpagos

This study investigates the effect of a predation gradient on the female life history traits of the poeciliid live‐bearing fish Phalloceros harpagos from a tropical stream in Brazil. Females’ length at maturity, somatic dry mass, reproductive allotment and fecundity varied significantly among predation sites. Phalloceros harpagos from the high‐predation site showed smaller size at maturity and somatic dry mass, greater reproductive allotment and higher fecundity than the nonpredation site. In all sites, we observed superfetation: pregnant females with two broods at different developmental stages. The presence of superfetation was not observed before in other congeneric species, and it may represent an additional independent evolutionary origin of superfetation in the fish family Poeciliidae. Matrotrophy, the postfertilisation maternal provisioning of nutrients to developing embryos throughout gestation, was observed in all three sites, with values of the matrotrophy index above two. The population under high predation pressure showed the highest degree of matrotrophy (embryos quadruplicate their dry mass during development) and the greatest percentage of females with superfetation (44.4%). Some life history traits responded more strongly to predators’ presence and others to predator density. These results suggest that different predation regimes shape female life history traits, increasing fecundity in high‐predation sites. The results also suggest a link between the cost of reproduction and the evolution of matrotrophy and superfetation, potentially to reduce the risk of predation without reducing fecundity.     

不同施肥模式下轮作制度引起的土壤磷素有效性变化及其影响因素

[目的]探究不同轮作体系对土壤磷素有效性的影响,评估不同轮作体系土壤磷素活化潜力,为农田磷素高效利用提供科学依据.[方法]试验于2018—2020年在江苏省如皋市农业科学研究所开展,设置水稻-小麦(R-W)、水稻-油菜(R-O)、水稻-包菜(R-C)、水稻-闲田(R-F)4个轮作模式,每种轮作模式下设置3种施肥处理,分...     

影响自主学习的主要因素分析及模式构想

结合我国的大学英语教育现状和学生特点,指出学习策略的培养、认知风格的差异、心理和情感因素以及教师在自主学习中的作用,已经成为建构合理的自主学习模式的重要因素,并对这些因素进行分析,提出建立适合中国学生尤其是大学新生的自主学习模式的构想。     

优质鸡蛋研发现状及安徽优质蛋鸡业科技策略

综述了国内优质蛋鸡业概况、影响蛋品质的因素、育种技术及安徽优质蛋鸡业科技策略,以更好地了解安徽优质蛋鸡业发展潜力,使安徽优质家禽业得到全面发展。