Inheritance and potentials of a mutated dwarfing gene ndf1 in Brassica napus

A dwarf mutant ‘NDF‐1′, approximately 70 cm high, was derived from a 200‐cm high doubled haploid (DH) line ‘3529’ (Brassica napus), seeds of which were jointly treated with chemical inducers and bombardment of fast neutron. The leaves of the ‘NDF‐1’ mutant were wrinkled and thicker compared with the wild‐type control. The mutant had much lower values than its original parents for all agronomic traits, except for its seed weight. A genetic analysis revealed that dwarfism is under the control of a major gene (designated as ndf1) with a mainly additive effect and non‐significant dominance effect. Because of the high level of resistance to lodging, breeding programmes for double low dwarf oilseed rape and heterosis utilization were initiated. Some new dwarf strains with improved agronomic performance were developed. The hybrid of the cross between the tall parent and the dwarf line showed increased harvest index and significantly higher seed yield than the tall parent or the control variety ‘Zhongyou 821’ and presented an estimated heterosis vigour rate as high as 12.5–25.8%. The dwarf trait will be a promising marker for a simple, economic and efficient way to control the purity of F₁ hybrid varieties in hybrid production of B. napus.     

Effects of climate on different potato genotypes 1. Radiation interception, total and tuber dry matter production

In 11 field trials in Rwanda, Tunisia and The Netherlands, the total dry matter production and tuber dry matter production of eight potato cultivars were analysed in terms of radiation interception and radiation use efficiency. The variation in length of the growing season was the most important factor explaining the differences in both total and tuber dry matter production among cultivars and sites. Radiation interception was the most important factor because the radiation-use efficiency was negatively correlated with radiation intensity and the variation in harvest index was of minor importance. Variation in length of the growing season among sites was related to daylength and temperature, in that shorter days at emergence and higher temperatures throughout the season resulted in a shorter growth cycle. The extent of these effects differed among cultivars, and it was concluded that climatic effects on tuber dry matter production could be attributed to the effects of temperature and daylength on the length of the growth cycle.     

农业标准化生产及其管理系统开发平台研究

分析中国农业标准化生产现状，发现其中存在的问题，提出与农业信息技术结合是解决问题的途径之一。而专家系统开发工具（平台）是农业信息技术的关键技术之一，它作为一种开发专家系统的通用工具，使农业领域专家无需掌握过多的编程知识就能建造性能良好的专家系统，从而能有效克服目前农业标准化生产中存在的问题。基于此介绍了将农业标准化生产和专家系统开发平台结合起来建立农业标准化生产管理系统开发平台的建立基础、设计思路、技术路线以及平台功能，并阐述了农业标准化生产管理系统开发平台的应用前景。     

区域棉花生产系统变化趋势分析与预测

利用棉花生产系统时间序列数据,分析江苏省区域棉花单产、种植面积和总产等生产指标的变化特征及趋势,结果表明除苏南外,棉花单产呈增加趋势,苏中棉花单产减少的可能性大于苏北;种植面积呈明显减少趋势;总产变化区域间差异较大,全省棉花总产呈现减少趋势,苏南、苏中为明显减少趋势,苏北表现为增长趋势。利用综合增长率或减少率法,分别建立悲观、一般、乐观条件下的棉花生产系统预测方案,并以实际生产指标值为基数,预测未来棉花的单产、种植面积和总产。     

Seed production and breeding potential of the fluted pumpkin,Telfairia occidentalis

Summary Studies during 1980–1987 relating to seed production of the fluted pumpkin (Telfairia occidentalis Hook. f.) are summarized. Essentially, the dioecious nature of the crop makes sex-ratios of plants affect the number of fruit-bearing females. Overall, about 50% of plants are female, of which some 15% are fruitless. Each fruit-bearing female has 1.5 fruits that contain 60 seeds. The mean weight of seeds is 15 g, and 74% of this total seed weight comprise the seed kernel which contains about 40% oil. Thus, a yield estimate of seed kernels reaches 1.9 t/ha; an output that is superior to that of most other oil seeds now being exploited for seed oil and cake in Nigeria. Measures to raise seed yields and the possibility of breeding work are discussed.     

农业工程技术对发展农村生产力的作用

提出乡级经济是农村经济发展的基本单位,发展农村经济的关键是发展农村生产力。在阐述农村生产力内涵的基础上,系统地论述了农业工程技术对农村生产力诸要素质和量以及结构优化方面所表现的功能,并从当前农业生产对农业工程技术实际需求出发,进一步论证了农业工程技术在农村经济发展中所发挥的作用。     

建设江西优质粮仓确保国家粮食安全

江西省是我国13个国家粮食生产基地之一,是保证50年不断为国家提供商品粮的重要省份。为进一步发挥江西省粮食生产潜力,向国家提供更多的商品粮,本文根据多年的研究结果,针对江西省粮食生产的战略地位,建设优质粮仓的资源潜力与关键问题,提出建设优质粮仓的有关建议,供有关方面参考。     

厌氧污泥发酵制氢工艺试验研究

试验研究了酸处理、碱处理、热处理、超声波预处理厌氧污泥发酵产氢的产氢量，选择产氢量最高的热预处理后的污泥作为混合微生物系，以葡萄糖为基质，研究了温度、pH值、底物浓度对厌氧污泥发酵产氢量的影响。结果表明，发酵的温度、pH值、底物浓度是影响热处理污泥发酵产氢的3个重要因素。厌氧污泥发酵产氢的最适pH值为6.0，最适葡萄糖浓度为5 g/L，最适温度为45℃。     

低温对仔猪生产的影响及其机制

仔猪死亡是养猪生产面临的重大问题，由于初生仔猪要求的环境温度高达３４℃，仔猪在初生后受寒是导致其被压死、饿死、虚弱死及腹泻死亡的重要因素。综述了低温对仔猪体温、初乳吸收和腹泻发生三方面的影响及机理，并提出了防治建议。