Problems of Breeding for Improved Standing Ability in Dried Peas, Pisum sativum L.

Standing ability is a major component of combining ability and yield stability in dried peas. In performance trials during 1986–1988 commercial varieties and new breeding lines were evaluated for standing ability at one location. Standing ability was measured by visual scores, crop height and standardized crop height (crop height in percent of plant length) at several observation dates during the generative phase. Visual scoring proved to be the most suitable method for the measurement of standing ability as far as time requirement and precision are concerned.
Considerable differences between years and varieties were found for both the course of lodging during the generative phase and the standing ability shortly before harvest. Several, at least three or four measurements of standing ability should be done during the generative phase. Also highly significant variety x year interactions were observed. Heritability values estimated for different parameters of standing ability were medium to high as compared to plant length and maturity date (high) or grain yield (low).
In general, standing ability of the semi-leafless varieties proved to be much better than standing ability of the conventional ones. However, the semi-leafless plant type was not always associated with an improved standing ability.
Problems relating to the methods of measurement of standing ability, its phenotypic expression and variability are discussed.     

Genotype × Environment Interaction in the Andean Grain Crop Quinoa (Chenopodium quinoa) in Temperate Environments

Ten varieties of quinoa with origins ranging from latitude 39° S to 12° S and from sea level to an altitude of 3,800 m were grown on two soil types in two years in Cambridgeshire, England, in order to assess the extent and nature of genotype × environment (G × E) interactions and identify genotypes suited for cultivation at temperate latitudes. There was evidence that varieties differed in their susceptibility to water logging during germination. Plant height was strongly influenced by competition with weeds, and varieties differed in their susceptibility to this. The number of days to anthesis and to maturity were strongly dependent on the variety, but these periods were generally longer following an earlier sowing. The grain yield was also strongly dependent on the variety, but weed competition, a micronutrient deficiency and bird damage affected the varieties differently. Varieties originating at high latitudes gave the highest yields, about 5,000 kg/ha. Earliness and yield were strongly associated at the level of variety means, but the pattern of G × E interaction differed among the variables measured.     

松嫩平原南部羊草草地水分生态环境分析

根据1985～1989年的试验,对松嫩平原南部天然羊草(Aneurolepidium chinense)草地的水分生态环境进行了分析。研究表明:松嫩平原南部羊草草地年水分收支基本相等,但收与支的时间格局不一致,6月明显干旱,7月末地表暂时性积水;土壤含水率在生长季初期(4月)最高,雨季来临前(6月)最低;空气相对湿度在整个生长季中均较低,生长季初期尤为明显;人类对草地的过度利用已对水分生态环境造成严重的不良影响。生长季前期干旱抑制植物同化器官的充分生长和发育,使其不能有效利用雨季的大量降水;空气干旱降低植物的 CO_2同化量,二者都制约草地生产力的提高。本文还从治标和治本两个角度探讨了改善松嫩羊草草地的水分生态环境,提高生产力的途径。     

水稻穿梭育种研究新进展

概述了８０年代发展起来的新的育种途径—水稻穿梭育种法研究的进展。在理论上初步探明了水稻穿梭育种选择的有效性及其选择规律，在实践中已育成一批各具特色的新品种，有的并用于生产。”同时展望了发展前景。     

水稻节水灌溉模式试验研究

以水稻非充分灌溉试验的大量实测资料为基础，分析了不同稻田水分状况对水稻主要生态环境因素的影响，讨论了节水灌溉条件下水稻的生理机制及产量形成特点，提出了水稻高产省水的合理灌溉模式。     

The use of getting up and lying down movements in the evaluation of cattle environments

The aim of this review is to find out if getting up and lying down movements can be used as one of several parameters when evaluating different cattle environments. Getting up and lying down movements are performed according to innate movement patterns. An unsuitable environment can cause these movements to become incomplete or abnormal and so lead to injuries. Physiological measurements at lying down show a greater change in tethered cattle than in cattle kept on deep litter. In short stalls the use of certain types of tethers and the height of the manger edge affect the normal getting up and lying down movements. Unsuitably designed cubicles in loose housing systems can lead to changed movement patterns. Calves and fattening bulls have fewer lying down and getting up movements and longer lying intervals on slatted floors than on deep litter. Calves kept in small individual crates carry out a large percentage of their lying down and getting up procedures abnormally. In this review it is shown that it is possible to make improvements in the environment of cattle by using results from studies of these behaviour patterns. The conclusion is that getting up and lying down movements can be used as one of several parameters when evaluating different cattle environments.     

Factors Affecting Fertility According to the Postpartum Period in Crossbred Dual-Purpose Suckling Cows in the Tropics

To determine the relationship between first service conception rate (FSC) and the postpartum period (PP), 6160 calvings from 2250 crossbred dual-purpose cows were analysed. The effects of breed predominance (BT: Bos taurus and BI: Bos indicus), season of service (dry, intermediate and humid), parity (1 or 2 and more), agroecological region (Sub-humid and Dry Tropical Forest) and milk production were studied. The postpartum period was grouped according to the calving–first service interval as G1 ≤ 60 days (n = 1889); G2 > 60 ≤ 90 days (n = 1436); G3 > 90 ≤ 120 days (n = 1030); and G4 > 120 days (n = 1805). Data were analysed by chi-squared test. The overall mean for FSC was 58.2% and was lower in G1 (p < 0.01). All PP showed a breed effect on FSC, with mean values of 61.6% and 53.3% for BI and BT, respectively. Season of service also affected FSC, which was significantly lower during the humid period: 51.2% versus 57.4% and 61.5% for the intermediate and dry periods (p < 0.01), respectively. Parity and environmental effects were not observed on FSC. Levels of milk yield did influence the FSC, which decreased from 66.7% and 61.0% for milk yields of < 1500 kg and between 1501 and 2000 kg to 46.0% in milk yields > 2000 kg (p < 0.01).     

水稻边际优势利用栽培增产的生态原因研究

对大小垄栽培群体和30cm等行距栽培群体不同层次的光照强度、群体行间温、湿度等生态因子及每穴穗数、每穗实粒数和单穴生产力三个产量性状和不同分蘖时期每穴茎数的边际效应指数进行了研究。结果表明,大小垄栽培群体下部的光照强度和透光率显著增加,行间温、湿度降低,使群体内部的光、温条件得到改善。每穴穗数、每穗实粒数和单穴生产力及不同分蘖时期每穴茎数的边际效应指数降低,说明实行大小垄种植后,群体内部的长势与边行的差距缩小,群体内部个体的生长优势得到发挥,达到了利用边际优势增产的目的。     

研究效益的未来经济分析：高粱晚施氮素的原因

研究效益的未来经济分析：高粱晚施氮素的原因——（Ｐ．Ｄ．Ｃｈｕｄｌｅｉｇｈ等），ＩｎＰｒｏｃｅｅｄｉｎｇｓｏｆｔｈｅＳｅｃｏｎｄＡｕｓｔ－ｒａｌｉａｎＳｏｒｇｈｕｍＣｏｎｆｅｒｅｎｃｅ，Ｇａｔｔｏｎ，４ｔｏ６Ｆｅｂｒｕａｒｙ１９９２，Ｖｏｌ．２，Ｎｏ...     

大学城景观环境设计的生态对策--以广州大学城为例

在对我国大学城建设中面临的景观环境问题进行分析的基础上,提出了大学城景观环境设计的生态对策,并对广州大学城景观环境设计与建设的生态对策进行了探讨。