A reciprocal F1 monosomic analysis of the genetic control of time of ear emergence,number of leaves and number of spikelets in wheat (Triticum aestivum L.)

Summary A reciprocal F₁ monosomic analysis of chromosomal differences between Spica and Bersée was carried out under controlled environment conditions. Chromosomes associated with differences in days to ear emergence, number of leaves and number of spikelets were identified. The results indicated that chromosome 2B of Spica carries a photoperiod insensitivity allele at the Ppd ₂ locus. Both Spica and Bersée appear to have a vernalization insensitity allele at the Vrn ₂ locus on chromosome 5B. On chromosome 3A, 4B, 4D and 6B factors were found with major effects on earliness per se, diffeences in ear emergence and number of spikelets which were independent of photoperiod and vernalization. The possibility that these factors influence growth rate is discussed.     

Inheritance of firmness in raw cucumber (Cucumis sativus L.) fruit

Summary Inheritance of raw cucumber fruit texture (Magness-Taylor Fruit Pressure Tester firmness) was investigated over a 4-year period from 1971–1974. Results from 2 separate but related experiments suggested that firmness was quantitatively inherited with sufficient additive effects to permit gain from selection. In a selection study within 4 F₂ populations derived from crosses between firm (Chipper and Gy3) and soft (Mincu and Green F) fruit type cultivars, variation among and within F₃ and F₄ families was significant but overall family means were not significantly higher than the high parent in any of the 4 crosses. Narrow sense heritability estimates for fruit texture were 0.80 in the Mincu × Chipper population and 0.77 in the Green F × Chipper, Mincu × Gy3, and Gy3 × Green F crosses. In a separate experiment, generation means analysis was used to assess the mode of gene action in 2 crosses: Green F × Chipper, and Gy3 × Green F. Additive genetic effects accounted for 98.8% and 99.3% of the total genetic variation within each cross, respectively.Scientific Journal Series Paper No. 9794.     

Inheritance of slow rusting to stem rust in wheat

Summary The inheritance of the slow rusting character was studied on F₅ progenies from seven spring wheat cultivars (Triticum aestivum) crossed in all possible combinations without reciprocals. The cultivars and their progenies were evaluated for slow rusting in 1974 and 1975 in epidemics of Puccinia graminis f. sp. tritici, races 15 and 151, and traces of other races. Slow rusting varied significantly among the parents and among the F₅ progeny of each cross. Transgressive segregation occurred in each cross, i.e. some progeny rusted more slowly than the parents and some faster. In crosses with both Idaed 59 and Kenya 58 the progeny distributions were skewed towards slow rust development but the distributions in the other crosses were normal. The genetic control of slow rusting was predominantly additive, and narrow sense heritability was approximately 80 percent. The number of segregating genes having an effect on slow rusting was estimated to be 2 to 12 pairs depending on the cross. Correlation between slow rusting and maturity was usually negative but in most crosses the relationship was small.Contribution No. 9624 from the Agricultural Experiment Station, University of Minnesota, St. Paul, Minnesota 55108.     

高产杂交籼稻新组合“特优649”产业化技术研究 I 密度及主要肥料因子对产量的影响

试验采用裂区设计，以肥料为主区，密度为副区，研究高产杂交籼稻新组合“特优649”的密度和氮肥、磷肥、钾肥施用量与产量的关系，结果表明：当密度为37.5万穴/hm2，或株行距为20cm×13.2cm，氮肥施用量为225kg纯氮/hm2，其N，P2O5，K2O的比例为1.0:0.5:0.8时，产量最高，平均达9.24t/hm2，最高达9.36t/hm2。据此提出产量指标为9.0 t/hm2以上的优化农艺措施组合为：每hm2密度37.5万穴，每穴插2粒谷秧，纯氮用量225kg，P2O5用量112.5 kg ，K2O用量180.0kg，其中基肥为猪牛粪22.5t+30kg过磷酸钙；试验还提出了相配套的水分运筹方法。     

矮败小麦群体改良的方法与技术

矮败小麦是具有矮秆基因标记的太谷核不育小麦. 根据轮回选择的基本原理和方法, 结合矮败小麦的特点, 我们逐步建立起一套简单易行的群体改良方法. 其主体技术包括组建一个好的基础群体, 利用控制授粉向群体引进优良基因, 通过开花前不良可育株的淘汰提高优良基因的频率, 借助于可育株与不育株的异交使基因重组, 以及正确地选     

Variation in dormancy duration of the U.K. wheat cultivar Hornet due to environmental conditions during grain development

Dormancy of wheat grains, the property conferring sprouting resistance, is affected by environmental conditions experienced during grain development. We investigated the hypothesis that short dormancy duration in U.K. wheat grain (thus a high risk of post-maturity sprouting) is related to weather conditions, i.e. high temperatures during grain development. Four wheat varieties were grown at four sites ranging from the far south to the far north of the country in the years 1995–1997,ensuring different temperature and rainfall conditions during grain development. This paper focuses on one variety, Hornet, which has a high sprouting resistance rating. Other varieties gave similar results. Serial laboratory germination tests (seven days, 20°C) at 100°C-dayintervals were used to measure dormancy duration, which was assessed from logistic curves fitted to the data. During the experiment the mean temperatures during grain development differed by over4°C, due to the site × year effect. Significant effects (p>0.05) of site and year (i.e. weather) on dormancy were found, when definitions of dormancy duration of D_A (number of days from anthesis to 50% germination in seven days at 20°C) or D_P (number of days from physiological maturity at 45% grain moisture to 50% germination) were used. Dormancy was markedly shorter in the hot, dry year 1995 compared to the cooler, wetter years 1996 and 1997. A relationship, as postulated by Belderok, between accumulated temperature during the dough stage of grain filling and dormancy duration was not found. However, a relationship of dormancy duration to the mean temperature during grain development was found, with short dormancy periods occurring after high mean temperatures were experienced. This revised version was published online in August 2006 with corrections to the Cover Date.     

Real-time Monitoring System of the Pump Station for High Press Water

With the development of industrial automation technology, the monitoring system becomes more and more important in the control system. The paper discusses the monitoring system design based on the pump station for high press water. At first, the paper introduced the base process and the control system of the pump station for high press water. The control system includes two parts: upper part and lower part. The control network consisted of some PLC controls the device in the system. Then the method of the OOP technology application to the monitoring system design are emphatically introduced and discussed. Finally, the paper briefly introduced the main function models and the key technologies.     

不同生育期干旱对冬小麦根冠生长发育的影响

用盆栽对冬小麦不同生育阶段进行不同程度水分调亏试验结果表明：拔节－孕穗期、抽穗－杨花期和灌浆－成熟3个阶段内土壤相对含水量（RW）上限为40％、50％、60％的水分亏缺均对作物的根冠发育产生了影响，拔节－孕穗期RW40％的水分亏缺处理使株高降低很多，低于不施肥的ck1，复水后也无法恢复。不同生育期的干旱均引起根冠干重的下降，根长则不同，水分亏缺有时会使根长增加，要看具体亏缺程度而定。根系不如冠部对干旱敏感，干旱促进营养物质向根的分配，减少了向冠部的运输，导致根冠比增大，另外，随生育期的推移，干旱对根冠比的影响减小。     

Methods for Rapidly Measuring the Lodging Resistance of Wheat Cultivars

Lodging resistance ratings for winter wheat cultivars are frequently based upon observations of lodging. This is an unreliable method because of the frequent occurrence of years without significant lodging events. It also does not distinguish between stem and root lodging resistance. This paper describes the development and testing of instrumentation and procedures for two field‐based methods to rapidly assess stem and root lodging resistance. Both methods used a specifically designed instrument for measuring the resistance of shoots against rotational displacement. Stem lodging resistance was assessed when the soil was dry and strong, whereas resistance to root lodging was assessed after the soil had been weakened by irrigation. Tests were carried out on 14 winter wheat cultivars grown at two sites in the UK during 2002. Both methods were able to detect statistically significant differences between the cultivars for their resistance to stem and root lodging. A comparison of these results with observations of lodging in the field showed that the methods accounted for about 60 and 50 % of the stem and root lodging respectively.     

平房仓不同风机降温通风对比试验

分别选用两种风机,对高大平房仓进行降温通风对比试验,将两种不同风机降温变化情况进行比较。结果表明,选用轴流风机降温通风,具有耗电低、能耗少、水分损耗低、降温均匀和操作简便等特点,适用于高大平房仓早期降温通风;选用离心风机降温通风,具有降温迅速、操作简便等特点,适用于高大平房仓紧急情况下的降温降水通风。