籼型光温敏两系不育系H153S的选育及应用

光温敏核不育系转育起点温度的高低是决定两系杂交水稻制种能否安全的关键因素之一,选育起点温度较低的光温敏核不育系可以显著提高两系杂交水稻制种纯度。本课题组利用系谱选育法,将播始历期较短、不育起点温度较高、农艺性状较好的两系不育系中间材料7HS006与播始历期较长、育性转换温度较低的绿102S进行杂交,选育出籼型两系不育系H153S,该不育系的不育起点温度较低,育性稳定,可繁性、农艺性状较好。H153S将在两系杂交水稻制种和推广中起重要的实际应用价值。     

两系杂交粳稻云光8号高产制种技术

两系杂交粳稻云光8号高产制种，应以稳定父母本播始历期为基础，缩短母本抽穗历期为原则，确定最佳抽穗扬花期和父母本播期；立足身田攻蘖，插足基本苗，加强肥水病虫管理，构建高产群体结构；采取综合措施，提高异交结实率；严格种子质量管理。     

115A等6个水稻三系不育系特性初步研究

对重庆市农科院水稻所选育的115A、Q1A、Q2A、2A、Q4A和82A等6个水稻三系不育系进行了分期播种试验和调查,结果表明:随播期推迟,播始历期缩短,幅度为15～20d,主茎总叶数减少,幅度为0.5～1.5叶.在调播差期时以叶差为准,误差较小.Q2A、2A、Q4A、82A制种的播差期可参考对照Ⅱ-32A进行调节.     

杂交水稻制种母本机插秧特性研究

选择8个不育系进行制种母本机插秧特性试验,设计不同用种量、不同秧龄期机插秧处理,研究对播始历期、主茎叶片数、群体苗数、穗粒结构及抽穗动态等特性的影响。结果表明:制种母本机插秧的播始历期比人工移栽延长,机插秧龄延长则播始历期明显延长,机插用种量对播始历期影响较小;母本机插秧的基本苗数、最高苗数、有效穗数、总颖花数均高于人工育秧移栽;机插秧与人工移栽、不同秧龄期处理、不同用种量处理的群体抽穗特性差异较小。根据母本机插秧特性的变化提出了杂交水稻制种母本机插秧的配套技术。     

籼型三系不育系泉6A生育特性初步观察

通过对不育系泉6A的生育特性的初步观察发现：泉6A主茎总叶片数为16叶,与Ⅱ-32A相同;播始历期比Ⅱ-32A长3d左右,属迟熟籼型三系不育系;该不育系花期集中,花时早,柱头外露率高,开颖角度大,有利于繁殖制种获得高产。     

4个新选育水稻光身光温敏核不育系的主要农艺性状及其配合力研究

光身稻具有光身、抗倒、米质优等特点,是重要的育种资源。为探明4个新选育的光身不育系的形态特征及其主要农艺性状的配合力表现,以非光身光温敏不育系Y58S及以其为亲本新选育的4个光身光温敏不育系为供试材料,考查其播始历期和上三叶、地上部节间形态特征;以5个不育系与6个恢复系按不完全双列杂交试验设计配置的30个杂交组合为供试材料,考查播始历期、株高、单株有效穗数、每穗总粒数、结实率、单株产量、穗长、千粒重、单株一次枝梗数等主要农艺性状指标,对供试组合主要农艺性状进行配合力分析。结果表明,新选育的4个光身不育系叶片、颖壳均光滑无毛,为典型的光身不育系;且上三叶形态特征优于对照Y58S,具有长、宽的特点。配合力方差分析结果表明,株高、单株有效穗数以及每穗总粒数主要受基因加性效应的影响;结实率、单株产量主要受基因非加性效应的影响;穗长、千粒重、单株一次枝梗数、播始历期既受基因加性效应的影响,又受基因非加性效应的影响,但加性效应的影响大于非加性效应。不育系的千粒重和结实率一般配合力方差大于恢复系,说明千粒重和结实率受不育系的影响较大;恢复系的播始历期、株高、单株有效穗数、穗长、每穗总粒数、单株一次枝...     

不同秧龄移栽对恢复系播始历期的影响

在制种实践中,恢复系402,298, 191的播始历期随秧龄的延长而延长.试验结果进一步表明,3～6叶期移栽,播始历期无明显变化;从7叶期开始,每推迟1叶移栽,播始历期延长2～3 d;当恢复系402,298移栽叶龄增至9叶,191增至10叶时,播始历期大幅缩短,且出现早穗.因此,在制种中父本移栽叶龄与父母本花期相遇的关系值得重视.     

温度对水稻不育系圣丰1A生育期影响的研究

研究了温度对水稻不育系圣丰1A生育期的影响,结果表明,水稻不育系圣丰1A为感温型品种,其播始历期随日平均温度的升高而降低;圣丰1A有效温度上限值为26℃,日均温度高于26℃时,生长速度随温度升高而降低。     

中早熟籼型三系不育系泉5A生育特性的初步观察

通过对不育系泉5A生育特性的观察发现：泉5A在4月初播种,播始历期为76d,比珍汕97A长1d,属中早熟籼型三系不育系;主茎叶片数为14叶,与珍汕97A相同;泉5A有良好的不育特性,开花习性好,在繁殖和制种方面可以获得比较理想的产量。     

培两优余红亲本生育特性初探

通过分期播种,对培矮６４Ｓ和余红１号的生育特性进行了初步观察,初步建立了余红１号和培矮６４Ｓ播始历期（ｄ）与播期,播始历期有效积温（℃）与播期的回归方程,并记载了亲本主茎叶数,为培两优余红制种高产提供了播差依据。     

SILAGE AND MILK PRODUCTION. A COMPARISON BETWEEN A DIPLOID AND A TETRAPLOID RYEGRASS

Two grass silages made in May and two made in August were compared in a 16-week winter-feediag experiment with 12 Ayrshire cows. The silages were fed ad lib. with a supplement of barley and groundnut cake. One of the silages made ia May and one made in August consisted of S24, a diploid variety of perennial ryegrass, and the other two of Reveille, a tetraploid variety of the same species. The silages made from Reveille had a higher content of lactic acid and a lower pH than those made from S24. The contents of digestihie organic matter in the silage DM made in May and August were 71.9 and 63.2%, respectively, for RevelUe and 68.7 and 60.9% for S24. Silage and total DM intakes were higher in the treatments where Reveille silages rather than S24 silages were fed. The mean daily milk yields from cows fed on the silages made in May and August were 39.6 and 34.5 lb (18.0 and 15.7 kg), respectively, for Reveille, and 38.0 and 34.1 lb (17.3 and 15.5 kg) for S24. The solids-not-fat (S.N.F.) and the crude protein contents of the milk averaged 8.64 and 3.29%, respectively, for Reveille, and 8.56 and 3.22% for S24. It is concluded (hat the silages made from Reveille were superior to those made from S24 as a feed for dairy cows.     

A LINEAR PROGRAMMING MODEL OF A HIGH-TEMPERATURE GRASS-DRYING ENTERPRISE

A linear programming model of a high-temperature grass-drying enterprise is described. From information about seasonal crop response, area of crop available and management constraints, the model determines the harvesting schedules which give greatest returns, less costs, from the enterprise over the season. This information can be used to examine the effects of long-term strategic decisions or to evaluate economically data on new crops from field experiments. For example, assuming a fixed cost of λ70,000/year for a high-temperature grass-drying installation and what is considered to be reliable input data for 1972, the returns less costs for optimum harvest schedules from different areas or crop varieties are:

A MANAGEMENT STUDY OF A BIRDSFOOT TREFOIL STRAIN TRIAL

A study of birdsfoot trefoil ( Lotus corniculatus L.) variety trial management was conducted with three variables, variety, stubble height and harvest date. The range in maturity for the three varieties used was 12-14 days. All plots were harvested thrice per season. The harvest dates for the two management regimes imposed differed by about two weeks for the first cut, by about one week for the second and were identical for the third cut. Stubble heights were two and six inches (5.08 and 15.24 cm).
Late-cut material outyielded that cut early, but suffered more winter damage. Material cut at a stubble height of two inches (5.08 cm) outyielded that cut at six inches (15.24 cm), but it also suffered more winter-killing. The ranking of varieties varied with management.
Alternative management schemes, designed to provide maximum yields and survival consistent with good-quality forage, are proposed and discussed.     

Development of A dormancy release technology: A review

Tuber dormancy can be released immediately in many commercially important potato cultivars by brief treatment (1-2 days) with bromoethane (BE) vapor at room temperature. The development of a large scale technology for BE application and safe removal through a capturing technique is necessary for successful application of this dormancy release method. Ideally, BE treatment of seed tubers would occur in a closed environment that would capture BE vapor in an unaltered form and allow controlled release for treatment of subsequent tuber lots. Results of screening studies for adsorbents indicate that the medium capacity activated carbon adsorbent, YAO has: i) a high capacity for BE; ii) a low capacity for water; and, iii) adsorbs and de-adsorbs BE quickly and easily. A plausible design of a large scale, dormancy release facility is presented. The proposed facility should meet present goals of the seed potato industry in an environmentally responsible manner.     

A COMPARISON BETWEEN A PADDOCK SYSTEM AND A 'WYE COLLEGE' SYSTEM OF GRAZING FOR MILK PRODUCTION

Two grazing systems, a paddock system and a ‘Wye College’ system, were compared in two 20-week experiments nsing 16 and 20 spring-calved Ayrshire cows in 1970 and 1971, respectively. A sward of S23 perennial ryegrass was used, and an average of 342 kg N/ha (305 lb N/ ac) was applied per annum. The paddock system had 28 separate paddocks; one paddock was grazed each day in rotation and occasionally topped in mid-season. The Wye College system had 4 plots of equal size and the cows were offered 1/7 of one plot each day; no back fence was used and surplus herbage was neither cut nor topped. The stocking rate on hoth systems was 1 cow per 0.20 ha (0.49 ac) in 1970 and per 0.16 ha (0.40 ac) in 1971. The mean daily milk yields per cow on the paddock and the Wye College systems were 16.2 and 15.3 kg (35.7 and 33.7 lb), respectively, in 1970; and 18.1 and 18.4 kg (39.9 and 40.6 lb) in 1971. The average annual output of milk was 13,500 and 13,150 kg/ha (1200 and 1170 gal/ac) on the paddock and Wye College systems, respectively. The fat and solids-not-fat (S.N.F.) contents of the milk were not significantly affected by the grazing system. It is concluded that the Wye College system was as effective as the paddock system in producing a high output of mUk per ha, but at a lower cost and with far fewer management decisions.     

广东育成无垩白软型优质籼稻不育系粤丰A

粤丰Ａ是由广东省农科院水稻研究所于1998年育成的国内第一个无垩白、低直链淀粉含量(14.3%)、软胶稠度(92ｍｍ)、低糊化温度(碱消值7.0)和香味浓的特优籼型三系不育系。该不育系千株群体不育株率为100%,花粉不育度为99.99%,柱头外露率达88.1%,稻瘟病全群抗性比达中抗水平。2000年10月在广州通过了由来自扬州大学、国家水稻改良中心、国家杂交水稻工程技术研究中心等单位著名专家的技术鉴定。专家组一致认为该不育系综合性状优良、不育性稳定、配合力强、异交结实率高、品质改良有重大突破,研究成果达国内外领先水平;其投入生产应用对推动我…     

A Rice Reference

Rice quality:A guide to rice properties and analysis reviews variability in rice characteristics and their effects on rice quality in great detail.After an introduction on rice quality that also explores paradoxes associated with the crop,the book goes on to examine rice physical properties and milling quality.This leads to a discussion of the effects that the degree of milling has on rice quality.The ageing of rice and its cooking and eating quality are comprehensively investigated in the following chap...