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81.
<正> An intergeneric hybrid between Aegilops tauschti Cosson. an annual diploid grass. and Psathyrostachys huashanica Keng, a perenmal diploid grass. The F_1 hybrid plant had chromosome number of 2n=2x=14. and was annual and morphologically intermediate between two parents. Meiotic analysis showed that this F_1 hybrid had an average of 12.20 univalants, 0.12 rod bivalents ad 0.004 quadrivalents at MI of the pollen-mother-cells. Multipolar division, irregular ctyokinesis. conjungation opening and coenocyte were observed in this hybrid. These results suggested that the D genome in the Ae. tauschii was distantly related to the N genome in the P huashanica. 相似文献
82.
Wheat transformation efficiency is closely related to several factors such as receptor genotype, constructed plasmid and selection procedure after bombardment or co-cultivation. In our study, several kinds of antibiotics, which were normally used in plant transformation to the selection genes of nptⅡ, bar and hpt,were tested for the optimal concentrations for wheat transformation. The results showed that 25 - 50mg/L of geneticin (G418) was suitable for the selection of nptⅡ, kanamycin or neomycin was not suitable for use. 3 5mg/L of phosphinothricin (PPT) or biolaphos could be used for the selection of bar, 100 - 150mg/L of hygromycin for the selection of hpt. Yangmai 158 and Yangmai 10 with high tissue culture response and good agronomic characteristics were screened from 25 potential Chinese wheat cultivars. The concentration changing of selectable agent in selection medium was helpful to obtain enough regeneration plantlets with strong root system. 相似文献
83.
研究了大豆荚粒性状的遗传变异度,验证了从引进品种(系)中进行系统选育的效果;测定了荚粒性状之间的遗传相关,为进行间接选育适应青海省地方品种积累科学资料;寻求比进行直接产量选育具有更高效率的选择指数。结果证明高寒地区进行大豆系统选育是行之有效的。 相似文献
84.
荞麦新品种吉荞9号选育报告 总被引:2,自引:0,他引:2
荞麦新品种吉荞9号,是经系谱法选育而成。吉荞9号具有优质、高产、抗逆性强、适应性广等优点。3年区域试验结果比对照品种增产28.44%,2年生产试验结果比对照品种增产26.58%。该品种1995年通过吉林省品种审定委员会审定。 相似文献
85.
广泛调查了温州地区野生地被植物种类,初步筛选出82种,利用园林植物应用的评价体系,进行评价分级,确定10种最适宜园林应用的地被植物,介绍6种地被植物园林应用情况. 相似文献
86.
农业机械节油是一个很重要的课题,牵涉的因素也很多,因此如何节约燃油不能只局限在某一点或某一方面.应通过正确的分析,了解和掌握农业机械节油的驾驶操作技术和车辆使用方法,并加以应用,才能达到农业机械使用中节油的目的. 相似文献
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88.
Genetic shifts are predicted to be greatest when highly diversematerial originating from an arid environment is bulk multiplied inirrigated and fertilised conditions. This is a key problem if largequantities of quality native seed are needed for restorationpurposes. In Presaharian Tunisia, we investigated two intermingledyield aspects of irrigated seed multiplication of Stipalagascae R. and Sch.: (1) nitrogen fertilisationand (2) selection for vegetative vigour. We set up twocontiguous nitrogen fertilisation trials, one withnon-selected seeds (from a nearby locality), and onewith selected seeds (48 clonal lines seeded in replicatedrows), and compared straw yields. Both selected and unselectedmaterial did not respond to more than 50 kg of nitrogenper ha. Unfertilised yields of both trials were similar,but the straw yield of fertilised selected material was more than100% higher than the straw yield of fertilised unselectedmaterial. In the trial with selected material, we collected straw andleaf yields per row, and scored each row for vigour and for phenologyduring three successive growing seasons. Genotypic differences inseed output and in mortality were large and mainly driven byvariation in potential straw for leaf ratios.The compromise between high yields and high genetic variation couldconsist of the following principles. (1) Create driergrowing conditions so that the actual straw forleaf ratio stays below the genotypic potential. (2) Useinstead fertilisation and selection to enhance seed yields.(3) Avoid bulk multiplication. 相似文献
89.
秦川牛系中国黄牛的代表性品种,主产于陕西关中地区,被毛紫红、肉役兼用、肉质优良。各级政府和科技人员历来都比较重视秦川牛选育改良工作,其肉用选育改良经历了"役用-役肉兼用-肉役兼用-肉用"的过程。尤其是近30年来,西北农林科技大学以保持秦川牛固有优点为基本出发点,以肉用为目标,长期坚持本品种选育,成功选育出秦川牛肉用新品系,其体型外貌和产肉性能得到了明显改善;通过引入国外肉牛品种杂交改良秦川牛,其后代产肉性能较秦川牛得以大幅提高。同时秦川肉牛产业化开发也已初具规模,产业集群效应开始显现,社会经济效益显著。本文介绍了秦川牛肉用选育改良过程、新品系特点和推广应用成效,讨论了中国黄牛选育改良应该注意的几个技术环节,对指导我国地方黄牛肉用选育改良及产业化开发,促进我国肉牛种业发展等具有重要意义。 相似文献
90.