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排序方式: 共有1011条查询结果,搜索用时 15 毫秒
1.
水霉属菌(Saprolegnia)分离培养技术研究 总被引:1,自引:0,他引:1
对水霉(Saprolegnia)的分离培养技术进行了探索,筛选出大麻籽、油菜籽、红花籽、苍蝇、蚜虫、小麦粒、玉米片、茶叶、葵花仁9种材料作为诱发水霉菌的诱饵。其中油菜籽能防止腐霉菌(Pythium)污染,是初步纯化菌种、排除杂菌的适宜饵料。同时发现控制温度能使水霉在最短时间内分别产生无性或有性繁殖。在水培条件下,25℃左右适合菌丝及无性器官的发育,有性器官却不能产生,而只有在15~17℃条件下才能使水霉很快进入有性生殖阶段;在加入200mg/L链霉素的CMA培养基上促发有性阶段则需要在25℃左右的温度下进行,方能缩短培养时间。 相似文献
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金定鸭的外型分化,受自然选择和性选择的双重影响。在生长发育过程中,依羽域在适应水域环境的重要性,雌雄金定鸭的正羽都按共同的羽域顺序陆续更换生长;与此同时,一日龄外型相同的异性雏鸭,逐渐表现出性双态,包括喙色、羽色、声音、性羽、体重和行为的表型差异,以满足繁殖竞争的需要。金定鸭性行为的出现以其性双态分化为基础,而性行为的分化又是其生理成熟的前提条件。对雄鸭的观察分析结果表明,性双态分化和性行为发育速度的快慢与其生理成熟的早迟是一致的。黑色尾羽的雄鸭,体重较小,其发育速度和性成熟均快于体重较大的白喙或端白尾羽者,因此,建议将尾羽颜色、性双态分化和性行为发育速度作为雄鸭的选育指标。 相似文献
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The salt‐sensitive Glycine max N23674 cultivar, the salt‐born Glycine soja BB52 population, and their hybrid 4076 strain (F5) selected for salt tolerance generation by generation were used as the experimental materials in this study. First, the effects of NaCl stress on seed germination, tissue damage, and time‐course ionic absorption and transportation were compared. When qualitatively compared with seed germination appearance in culture dishes, and tissue damages on roots or leaves of seedlings, or quantitatively compared with the relative salt injury rate, the inhibition on N23674 was all the most remarkable. After the exposure of 140 mm NaCl for 1 h, 4 h, 8 h, 12 h, 2 days and 4 days, the content of Cl? gradually increased in the roots and leaves of seedlings of BB52, 4076 and 23674. Interestingly, the extents of the Cl? rise in roots of the three experimental soybean materials were BB52 > 4076 > N23674, whereas those in leaves were just on the contrary. Secondly, by using the scanning ion‐selective electrode technique (SIET), fluxes of Na+ and Cl? in roots and protoplasts isolated from roots and leaves were also investigated among the three experimental soybean materials. After 140 mm NaCl stress for 2, 4 and 6 days, and when compared with N23674, slighter net Cl? influxes were observed in root tissue and protoplasts of roots and leaves of BB52 and 4076 seedlings, especially at the cellular protoplast level. The results indicate that with regard to the ionic effect of NaCl stress, Cl? was the main determinant salt ion for salt tolerance in G. soja, G. max and their hybrid, and the difference in their Cl?/salt tolerance is mainly attributed to the capacity of Cl? restriction to the plant above‐ground parts such as leaves. 相似文献
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Iñigo Loureiro María Concepción Escorial María Cristina Chueca 《Pest management science》2023,79(6):2247-2254
BACKGROUND
Cultivated bread wheat (Triticum aestivum L.) spontaneously hybridizes with wild/weedy related Aegilops populations, but little is known about the actual rates at which this hybridization occurs under field conditions. It is very important to provide reliable empirical data on this phenomenon in order to assess the potential crop–wild introgression, especially in the context of conducting risk assessments for the commercialization of genetically modified (GM) wheat, as gene flow from wheat to Aegilops species could transfer into the wild species genes coding for traits such as resistance to herbicides, insects, diseases or environmental stresses.RESULTS
The spontaneous hybridization rates between wheat and A. geniculata and A. triuncialis, which are very abundant in the Mediterranean area, have been estimated for the first time in the northern part of the Meseta Central, the great central plateau which includes the largest area of wheat cultivation in Spain. Hybridization rates averaged 0.12% and 0.008% for A. geniculata and A. triuncialis, respectively. Hybrids were found in 26% of A. geniculata and 5% of A. triuncialis populations, at rates that can be ≤3.6% for A. geniculata and 0.24% for A. triuncialis.CONCLUSION
The detection of Aegilops spp.–wheat hybrids in Aegilops populations indicates that gene flow can occur, although wheat is considered a crop with a low-to-medium risk for transgene escape. These data on field hybridization rates are essential for GM wheat risk assessment purposes. © 2023 Society of Chemical Industry. 相似文献7.
资源材料保存在作物遗传资源的研究与利用中起到非常重要的作用。该实验以不同来源的人工合成甘蓝型油菜KH106,KH109,KH111D为材料,以花序轴,子房,果柄为外植体研究其再生情况,结果表明,由芥蓝和小白菜人工合成的甘蓝型油菜KH106的再生频率极显著高于由羽衣甘蓝和白菜型油菜人工合成的甘蓝型油菜KH109和KH111;与花序轴和子房为外植体再生频率相比,以果柄为外植体平均再生频率最高,差异达到极显著水平;利用不同预处理培养基处理不同时间,结果显示不经过预处理直接接种到分化培养基上再生频率最高。 相似文献
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Sung-Je Choi Eun-Jeong Park Hirotoshi Endo Yukihiro Kitade Naotsune Saga 《Fisheries Science》2008,74(4):822-829
ABSTRACT: To investigate inheritance of chloroplasts and mitochondria (organelles) in the marine red alga Porphyra yezoensis , cleaved amplified polymorphic sequence (CAPS) profiles of the two strains, TU-2 and KGJ, as parental gametophytes and 44 hybrid sporophytes (i.e. female of TU-2 and male of KGJ) were examined. A carbamyl phosphate synthase small subunit gene ( carA ) and ribosomal protein S11 gene ( rps11 )-small subunit ribosomal RNA gene ( rns ) spacer region were used as molecular markers for the chloroplast and mitochondrial DNAs, respectively. Thirty-eight of 44 (86.4%) conchocelis colonies showed maternal banding patterns, five (11.4%) colonies showed biparental bands and one (2.2%) colony showed paternal bands in CAPS analyses both with chloroplast and mitochondrial markers. These results suggest that organelles of P. yezoensis are inherited uniparentally from the female parent. 相似文献