水稻广亲和光敏核不育系H52S的选育

利用常现杂交有种结合花药培养技术,筛选出具有广亲和特性的模型光敏核不育系H52S,其育性转换明显,不育期内不育株率与不有度均达100％,可育期内自然结实率达40％以上;将其与广亲和测试种杂交,F1结实率达80％以上,经初步亚种间配组分析,显示强大的增产潜力．     

Impact of different beer yeasts on wheat dough and bread quality parameters

In order to investigate the impact of different yeast strains from the species Saccharomyces cerevisiae on the dough and bread quality parameters, wheat flour was fermented using different beer yeasts. The results show that beer yeast strains could be included in the baking process since S. cerevisiae T-58 and S. cerevisiae s-23 provided adequate gas production and dough formation with superior structural properties like extensibility and stickiness to S. cerevisiae baker's yeast. The resulting breads show the highest specific volume with the highest slice area and the highest number of cells and the lowest hardness over time. The different yeasts had also an impact on the crust colour due to their abilities to ferment different sugars and on shelf life due to the production of a range of different metabolic by-products. According to this study it was possible to produce higher quality bread by using yeast coming from the brewing industry, instead of bread containing standard baker's yeast.     

不同密度和肥料对杂交棉主要农艺性状的影响研究

本文通过不同肥料和密度对杂交棉主要农艺性状的影响研究，结果表明，在22500株/ha—31500株/ha的密度水平和600kg/ha---1050kg/ha的施肥（折尿素，下同）水平范围内，各处理对杂交棉的生育期影响不大；而随着密度增加，杂交棉每株果档数减少、单铃重下降、衣分降低，有效铃增加，产量总体上呈增加趋向势；随着肥料水平增加，不同密度水平的产量性状因子表现不一致,，而较低密度时，除每株果档数外其余产量性状及产量均增加，而较高密度时，各产量性状及产量则表现先增后降，但二者均在移栽地区杂交棉适宜密度范围内。综合来看，生产上应以27000株/ha密度 和900kg/施肥水平为基础上，视田间具体条件，选择适宜的肥料和移栽密度水平。     

茶饼病的发生规律及综合防治研究

茶饼病只侵染茶树的幼嫩芽叶及嫩梢。担孢子越冬并为第二年初侵染源。病害的消长规律与温湿度、降雨量有密切关系,而湿度影响尤为显著。8—9月为发病高峰期。茶树不同品种和叶位与抗病性有一定的关系。经综合防治的茶园其发病率降低,产量增加。     

黄瓜病虫害绿色防控技术及示范成效

黄瓜病虫害种类多、危害大,传统用药方式严重影响产品质量和口感。为了保证直供上海的黄瓜达到无公害要求,对生产基地采取农业防治、生态控制、生物防治和物理防治相结合的绿色防控措施,化学农药使用量减少30%,综合防治效果在85%以上,有效减少了防治次数,降低了农产品的农药残留,667 m~2增产600 kg,增值600元左右。收到了较好的经济、生态及社会效益。     

An examination of Fe deficiency stress response in relation to Fe uptake in two sorghum hybrids and their parent cultivars

Two sorghum (Sorghum bicolor L. Moench) hybrids CSH‐10 and ‐ 11 and their parent cultivars 296‐A, SB‐1055 and MR‐715 were examined for their tolerance to Fe‐deficiency stress, and also Fe uptake. It was observed that there was greater reduction of pH of the nutrient media and more rapid recovery from chlorosis only in the female parent 296‐A, and to some degree in the hybrids, but not in the male parents. The results indicated that Fe uptake‐translocation were inversely related to their Fe stress tolerance.     

水轮发电机组模糊控制PI调速器研究

根据一种简化的模糊控制算法来设计模糊控制决策表的计算机自动生成软件,即所谓的“决策软件”。这是一种把PI控制与模糊控制有机地结合在一起的方法,能够实现水轮发电机组PI调速器参数按模糊规则近似进行在线自动调整的控制。     

中国主要栽培大麦变种及其分布

根据全国314个主要栽培大麦品种的书面材料和标本,鉴定出它们属于普通大麦种、二棱大麦和多棱大麦两个亚种,共82个变种,其中新变种28个。多棱大麦变种占83％,稞大麦多于皮大麦。变种中以稀穗、长芒、齿芒,穗和籽粒深色(黑、褐、紫、兰绿)、长毛小穗轴等类型占多数。二棱大麦以nutans和erectum,多棱大麦以pallidum,parallelum,pyramidatum,coelcste,revelatum和nudipyramidarum等变种分布较广。变种数、深色型变种和多棱大麦变种的分布频率都以青藏高原为最高。因此认为,多棱大麦是我国主要栽培类型,青藏高原可能是我国栽培大麦的起源中心。     

中国土壤微生物量的大小

The microbial biomass C, N and P of soils all over China were determined in this study to study their affecting factors. The results, about 100-417 mg C kg^-1 soil, 18-51 mg N kg^-1 soil and 4.4-27.3 mg P kg^-1 soil, showed the biomass C, N and P in linear relationship with the soil total organic C, toal N and soil organic P. The ratios of C: N and C:P, ranging from 5.6 to 9.6 and from 11.2 to 48.4 respectively, were affected by soil pH, texture, crop rotation, macroclimate, etc. The ratio of C:N in soil biomass increases gradually from the north to the south in China.     

Somatic hybrids between navel orange (Citrus sinensis) and grapefruit (C. paradisi) for seedless triploid breeding

Protoplasts from cell suspension cultures of ‘Bonnaza’ navel orange (Citrus sinensis (L.) Osbeck) were electrically fused with mesophyll protoplasts isolated from seedless ‘Red Blush’ grapefruit (Citrusparadisi). After 6 months of culture, a total of 20 plants were regenerated. Root tip chromosome counting revealed that 4 of them were tetraploids (2n = 4x = 36)and the rest were diploids (2n = 2x = 18) morphologically resembling the mesophyll parent. After 6 months of transplantation into the greenhouse, 4 of the diploidmesophyll regenerants unexpectedly flowered, but this phenomenon disappeared in the next year. This is the first report of precocious flowering in citrus via protoplast fusion. RAPD analysis further confirmed that the tetraploid regenerants were somatic hybrids while the diploid regenerants were mesophyll parent type. This somatic hybrid will be utilized as a possible pollen parent for improving the seedy pummelo cultivars in China by producing triploid seedless pummelo hybrid. The mechanism of early flowering was also discussed. This revised version was published online in July 2006 with corrections to the Cover Date.