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31.
两优667特征特性及高产栽培技术 总被引：1，自引：0，他引：1
两优667是福建省农业科学院水稻研究所育成的中籼型两系杂交稻新品种,2013年通过福建省品种审定。具有株叶形态好、产量高、熟期适中、米质较优、适应性广等特点。栽培上通过适时播种、培育多蘖壮秧、合理密植、推行配方施肥、科学管水、病虫害综合防治等技术措施,可获高产。 相似文献
32.
为摸索杂交稻品种民优5338相配套的早季高产栽培技术措施,采用正交设计法开展民优5338早季栽培的三因素(插植规格、每667m~2施纯N量、N肥施用方法)试验,结果表明:采用插植规格20 cm×20 cm、每667m~2施纯N量16 kg和N肥施用方法(基肥∶蘖肥∶穗肥=5∶3∶2)组合的栽培效果最佳,适宜生产推广。 相似文献
33.
通过分析农家书屋存在管理制度不完善、管理员专业素质不高、书屋作用没有得到有效发挥等问题,提出高校图书馆可在建立和完善长效机制、管理员培训、搭建科技文化下乡新平台等方面进行改进,为农家书屋管理和使用提供支持。 相似文献
34.
《Plant Production Science》2013,16(3):203-210
SummaryGenerally F1 hybrids from crosses between japonica and indica rice show variable degrees of sterility. Previous studies revealed that among the indica rice, the Aus type has sexual affinity with japonica cultivars giving higher fertility in F1 hybrids. Therefore, we made an effort to obtain higher grain yield by producing F1 hybrids between japonica and Aus-type indica. A field experiment was conducted to investigate the heterosis in these F1 hybrids for dry matter accumulation, spikelet fertility, yield and yield attributes, to find cross combinations with higher grain yield, and examined the relationships of grain yield with some agronomic characters. F1 hybrids flowered earlier than their parent cultivars. Heterosis for dry matter accumulation was positive at the panicle initiation stage, at heading and at maturity. The average heterosis for number of panicles, grain and straw yield per plant, number of spikelets per panicle and 1000-grain weight was positive. A few F1 hybrids showed positive heterosis for number of filled grains per panicle, spikelet fertility and harvest index; but the average heterosis for these traits was negative. Among the yield components, a higher number of panicles per plant and higher number of spikelet per panicle contributed to higher grain yield in F1 hybrids. A significant and positive relationship existed between spikelet fertility and grain yield per plant. The higher grain yield was attributed to higher dry matter production rather than higher harvest index in F1 hybrids, although low spikelet fertility limited yield potential in some F1 hybrids. 相似文献
35.
A. Gallais 《Euphytica》1988,39(2):95-104
Summary To discuss the utilisation of heterosis in plant breeding it is necessary to consider its genetic basis. In cross fertilized plants in which the phenomenon of heterosis is very important, such as maize, it appears that a great part can be explained by the mutation load. However in both autogamous or allogamous plants it is difficult to exclude a role of marginal overdominance which could justify hybrid variety production.To know in a relatively short time whether it will be better to develop lines or hybrids it is necessary to know the parameters (mean and variance) of the distribution of all varieties of a given type which can be derived from the breeding population. A numerical application allows the determination of the situations where the best single crosses will be better than the best lines. With some approximate values of the necessary parameters, the case of grain yield in maize and in wheat is briefly discussed.To develop lines or hybrids, a general strategy is given. Its main axis is population improvement which has to be adapted to the type of varieties to develop. It is shown that according to the situation the type of varieties to develop can change with time: single crosses can be more justified at the beginning and lines can be justified later if all heterosis were fixable. To develop hybrids the best scheme is reciprocal recurrent selection with half-sib or full-sib progenies followed by pedigree reciprocal selection initiated by full-sib progeny tests. With this strategy there is no problem of the prediction of hybrid performances. However it seems possible to develop some predictors of heterosis or of specific combining ability between two lines using some criteria of genetic distances. Preliminary results with distances computed from the behaviour of lines in a two-tester top cross design appears very stimulating.Communication given at the206th meeting of teh Genetical Society of Grain Britain 相似文献
36.
XIAO Guo-ying 《水稻科学》2009,16(3):235-239
In addition to weed control in direct seeding field of hybrid rice, herbicide resistance genes were used by Chinese scientists to increase and identify the purity of hybrid seeds, and to realize the mechanization of hybrid seed production. The elite restorer lines, such as Minghui 63, R752, T461, R402, D68 and E32 were transformed directly with herbicide resistance genes, in which D68 and E32 are restorer lines of two-line system and the others are of three-line system. Because almost all of important restorer lines are indica varieties and are recalcitrant in transformation, many herbicide resistant near-isogenic restorer lines were developed by sexual hybridization of indica and japonica varieties and backcross with indica restorer lines later, such as Ce 64, Minghui 63, Teqing, Milyang 46, R402 and 9311, in which 9311 is a restorer line of two-line system. The elite photoperiod-sensitive/thermo-sensitive genic male sterile lines, such as Pei'ai 64S, P88S, 4008S and 7001S, were transformed with herbicide resistance genes. A few herbicide resistant male sterile lines were developed through sexual hybridization and subsequently systemic selection, such as Bar1259S, Bar2172S, 05Z221A and 05Z227A. With the employment of herbicide resistant male sterile lines or herbicide resistant restorer lines, a few herbicide resistant hybrid rice combinations were developed, such as Xiang 125S/Bar 68-1 and Pei'ai 64S/Bar 9311. Based on herbicide resistance, the research was marching on to investigate the parental lines of hybrid rice with insect resistance, drought tolerance, etc. 相似文献
37.
Weeds are a major constraint to rice (Oryza spp.) production in West Africa. Superior weed competitive rice genotypes may reduce weed pressure and improve rice productivity. Two upland and two lowland experiments were conducted in southern Benin to examine genotypic variations in weed-suppressive ability and grain yield under weedy conditions, and to identify plant characteristics that could be used as selection criteria for improved weed competitiveness. A total of 19 genotypes, including Oryza sativa and Oryza glaberrima genotypes and interspecific hybrids developed from crossing O. sativa and O. glaberrima, were grown under weed-free and weedy conditions in an upland with supplemental irrigation and in a flooded lowland. In weedy plots, hand weeding was done once or not at all. Mean relative yield loss across all genotypes due to weed competition ranged from almost 0% to 61%. Large genotypic variations in weed biomass and grain yield under weedy conditions were found. Visual growth vigor at 42 and 63 days after sowing (DAS) under weed-free conditions significantly correlated with weed biomass at maturity in both upland and lowland experiments (R2 = 0.26–0.48). Where weed pressure was low to moderate, with mean relative yield loss less than 23%, the multiple regression models using grain yield and plant height at maturity or only grain yield measured under weed-free conditions as independent variables could explain 66–88% of the genotypic variation in grain yield under weedy conditions. At higher weed pressure (mean relative yield loss: 61%), as observed in one of the upland experiments, biomass accumulation of rice at 42 days after sowing was associated with higher grain yield under weedy conditions. Biomass accumulation also significantly correlated with visual growth vigor at the same sampling dates. Therefore, we conclude that grain yield, plant height at maturity and visual growth vigor at 42–63 DAS under weed-free conditions appear to be useful selection criteria for developing superior weed competitive rice genotypes. 相似文献
38.
Jing LI Peng XU Jia-wu ZHOU Feng-yi HU Xian-neng DENG Zhi-wei CHEN Da-yun TAO 《水稻科学》2011,18(2):110-115
Hybrid sterility between Oryza glaberrima and O. sativa seriously hampers the introgression of favorable genes from each other. In order to further understand this issue, identification and isolation of hybrid sterility QTLs as single Mendelian factors are an effective strategy. A genetic map was constructed using a BC1F1 population derived from a cross between an O. sativa japonica cultivar and an O. glaberrima accession. Four main-effect QTLs for pollen sterility were detected in the BC1F1. Five BC8F1 advanced backcross populations were developed via successive backcrosses based on phenotype and molecular selections. The BC8F1 populations showed bimodal distribution for pollen fertility and could be classified into semi-sterile and fertile types, fitting single Mendilian factor inheritance ratios. Three QTLs detected in the BC1F1 corresponding to qSS-3, qSS-6a and qSS-7 were mapped on chromosomes 6, 3 and 7, respectively, as single Mendilian factors. 相似文献
39.
简要介绍了湖南农业大学及图书馆发展历史,并分析了图书馆发展现状,指出该馆具有管理模式先进化、设施设备现代化、馆藏资源特色化、读者服务专业化的特色,其中重点分析了图书馆管理的几大组成部分。希望通过介绍分析,完善该图书馆事业发展全貌。 相似文献
40.
图书馆业务外包的实施策略 总被引：12，自引：0，他引：12
唐定海 《农业图书情报学刊》2004,16(12):89-91
业务外包是一种新型的图书馆管理方法。本文介绍了图书馆业务外包的概念、内容、作用,探讨了实施图书馆业务外包的相应策略。 相似文献