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三种胡卢巴属植物的核型比较 总被引：3，自引：1，他引：2
对藏青胡卢巴、齿荚胡卢巴和胡卢巴采用常规根尖压片技术进行的核型分析表明，三种植物的核型分别为２ｎ＝２ｘ＝１６＝２Ｍ＋１４ｍ（２ＳＡＴ）、２ｎ＝２ｘ＝１６＝４Ｍ＋１０ｍ＋２ｓｍ、２ｎ＝２ｘ＝１６＝４Ｍ＋１０ｓｍ＋２ｓｔ，分属１Ａ、２Ａ和３Ａ类型，演化程序可能为藏青胡卢巴→齿荚胡卢巴→胡卢巴。 相似文献
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西藏砂生槐的核型分析 总被引：1，自引：0，他引：1
西藏砂生槐的染色体数目为２ｎ＝１８，其核型公式为２ｎ＝２ｘ＝１８＝１２ｍ（４ＳＡＴ）＋６ｓｍ，即６对中部着丝点染色体和３对近中部着丝点染色体；第２对染色体的短臂和第４对染色体的长臂上各带１对随体。 相似文献
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用根尖压片法对盐豆木染色体核型进行研究的结果表明，盐豆木是二倍体植物，体细胞染色体数为２ｎ＝１６，染色体基数为８，染色体组成为２ｎ＝１６＝１６ｍ，属对称该型（１Ａ型）。 相似文献
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四种豆科牧草的染色体核型分析 总被引：3，自引：0，他引：3
运用常规的根尖细胞压片法，对４种豆科牧草的染色体数目、核型进行了研究。建立的核型公式如下：伊犁苜蓿为２ｎ＝３２＝２８ｍ＋４Ｓｍ，黄花苜蓿为２ｎ＝３２＝３２ｍ，扭果苜蓿为２ｎ＝３２＝８ｍ＋４Ｓｍ，百脉根为２ｎ＝１２＝１０ｍ＋２Ｓｍ。 相似文献
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用根法压片法对顶羽菊染色体核进行研究的结果表明，顶羽菊是二倍体植物，体细胞染色体数为２ｎ＝２６，染色体基数为１３，染色体组成为２ｎ＝２ｘ＝２６＝２２ｍ＋４ｓｍ，属不对称核型（ＩＢ型）。 相似文献
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星星草群落地上生产结构、现存量季节动态和净初级生产力的研究 总被引：7，自引：0，他引：7
对星星草（Ｐｕｃｃｉｎｃｅｌｌｉａｔｅｎｕｉｆｌｏｒａ）群落的生产结构、现存量季节动态和地上净初级生产力（ＡＮＰＰ）的研究结果表明：同化系统（ＡＳ）和非同化系统（ＵＡＳ）的现存量分别集中分布于地上０～２０ｃｍ和０～３０ｃｍ的范围内，属典型的下繁型草地群落。其ＡＳ．ＵＡＳ和地上总现存量（Ｙ）在空间不同层次（ｘ）的积累规律表现为变型双曲线函数Ｙ＝ａ＋ｂ／ｘ形式。星星草种群及其群落地上生物量增长规律符合Ｌｏｇｉｓｔｉｃ增长模型；其地上现存量季节动态呈二次抛物线方程Ｙ＝ａ＋ｂｘ＋ｃｘ２形式。该群落的ＡＮＰＰ为２００．９８／ｍ２·ａ。 相似文献
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山羊内毒素休克诱发脂质过氧化作用及山莨菪碱对其影响的研究 总被引：13，自引：0，他引：13
本文将３０头杂交山羊分成３组,第１组（ｎ＝６）为对照组,第２组（ｎ＝１２）静注大肠杆菌内毒素复制休克模型,第３组（ｎ＝１２）在第２组基础上提前１０ｍｉｎ静注山莨菪碱性注射液,检测１２ｈ内不同时间血清丙二醛（ＭＤＡ）含量,总ＳＯＤ,Ｍｎ－ＳＯＤ,ＣｕＺｎ－ＳＯＤ,ＣＡＴ和血液ＧＳＨ－Ｐｘ活性,结果表明,第２组血清ＭＤＡ含量明显增加（Ｐ〈０．０１）,血清Ｔ－ＳＯＤ,Ｍｎ－ＳＯＤ,ＣｕＺｎ－ＳＯＤ,ＧＳ 相似文献
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对黑龙江野生燕麦和栽培燕麦的染色体组型观察分析，绘制核型模式图，并进行比较研究，结果表明：黑龙江野生燕麦与栽培燕麦的六倍体染色体数目皆为２ｎ＝６ｘ＝４２。ＮＯ．１、ＮＯ．３、ＮＯ．６染色体黑龙江野生麦皆为“ｍ”型而栽培燕麦皆为“ｓｍ”型之外，蓁的１８对染色体尖型皆一一对应一致。黑龙江野生燕麦的核型公式为２ｎ＝６ｘ＝４２＝２８ｍ（２ＳＴＡ０＋１４ｓｍ，栽培燕麦的核型分析中未发现有随体染色体。另外，黑 相似文献
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刈割期和留荐高度对新麦草产草量及品质的影响 总被引：16，自引：2，他引：14
１９９９年５月～９月在华北农牧交错带研究生育期和留荐高度对新麦草产草量及品质的影响,结果表明,以抽穗期刈割头荐留荐４ｃｍ全年割三次的干草总产量最高,（２０６０．５１ｋｇ／ｈｍ＾２）,其次是初花期刈割头荐留荐１０ｃｍ（１９５１．８４ｋｇＤＭ／ｈｍ＾２）,粗蛋白质总产量最高的处理是抽穗期刈割头荐留荐４ｃｍ（４７０．２９ｋｇＤＭ／ｈｍ＾２０,其次是初花期头荐刈割,留荐４ｃｍ（４２４．２６ｋｇＤＭ／ｈｍ＾ 相似文献
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《Strength and Conditioning Journal》2005,58(2):177-183
Crested wheatgrass (Agropyron cristatum [L.] Gaertn.) and Russian wildrye (Elymus junceus Fisch.) are commonly used for reseeding in the more xeric Mixed Prairie of the Canadian prairies because they are perceived to be more productive than native species. However, they have been implicated in soil deterioration. The objectives of our study were to compare the aboveground net primary production and soil organic carbon (C) among monoculture communities of selected native grass species, crested wheatgrass, and Russian wildrye and to compare the native grass monocultures with their mixtures. In 1995, a 5-year study was initiated on Dark Brown Chernozemic (Typic Haploboroll) soil near Lethbridge, Alberta. Ten treatments consisting of monocultures of introduced and selected native species and mixtures of native species were established in a randomized complete block design with 4 replications. Aboveground net primary production and soil organic C were measured. Monocultures of 2 native species, green needlegrass (Stipa viridula Trin.) and blue grama (Bouteloua gracilis [H.B.K.] Lag. ex Steud.), were more productive than crested wheatgrass or Russian wildrye under both normal moisture and drought conditions. Monocultures of these native species also tended to be more productive than their mixtures. The western wheatgrass (A. smithii Rydb.) monoculture and the western wheatgrass–blue grama mixture experienced the greatest yield reduction as a result of drought. Treatment effects on soil organic C were not detected (P > 0.05) 5 years after seeding. Soils of the June grass (Koeleria macrantha [Ledeb.] J.A. Schultes f.) community had less (P < 0.05) macro-organic C than most other treatments. 相似文献
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施氮与株丛切割对退化新麦草草地的改良效果 总被引：11，自引：0，他引：11
本文研究了施氮肥和株丛切割对退化新麦草人草地生产性能的影响，结果表明，施氮肥和株丛切割提高了新麦草草地生产性能和生产力。此外，施氮肥可改善牧草品质及土壤牮氮能力。株丛切割和施氮肥（１２０ｋｇ／ｈｍ＾２）相结合与单施氮肥相比，成本较低，对退化新麦草草地的改良效果良好，年均产草量２６７９．５ｋｇＤＭ／ｈｍ＾２。 相似文献
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灌水对新麦草种子产量及产量构成的影响 总被引：4，自引：2，他引：2
研究不同灌水次数和灌水量对新麦草(Psathy rostachys juncea)种子产量、产量构成和生长特性的影响。结果表明:不同灌水次数的小穗小花数、小穗种子数和千粒重间差异显著(P<0.05),生殖枝数和生殖枝小穗数差异不显著;从返青到收获,灌水4次(返青期、拔节期、抽穗期和灌浆期)生殖枝数和小穗种子数最高,其实际种子产量也最高,达593.3 kg/hm2;不同灌水次数对生殖枝高度和穗长影响显著(P<0.05);不同灌水量对种子产量和产量构成的影响不显著。 相似文献
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新麦草种子成熟过程中活力变化的研究 总被引：18，自引：5，他引：13
１９９７年对新麦草种子成熟过程中活力变化进行了研究。研究结果表明：新麦草种子活力随着种子的成熟而逐渐增加并于种子获得最大干重时，活力达到最高。试验所选的指标均反映了新麦草种子活力变化状况，种子发芽率不能直接反映种子活力的变化，但它仍是检验种子活力不可缺少的指标。单项活力指标不能全面反映活力的变化，需采用多种指标，进行综合分析。 相似文献
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为选择适于本地区栽培的高产、优质多年生禾本科牧草,于2014年至2015年在同仁县年都乎乡进行不同多年生禾草的引种试验。结果表明,四种多年生禾草都能适应本地区,但相比之下,在平均草层高度和产量方面多叶老芒麦明显高出其它三种牧草,更适宜在该地区大量种植,可以作为人工草地建设和天然草场改良的优良牧草。 相似文献
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Relative benefit of introducing forage species to the Northern Great Plains have been examined with contradictory conclusions. In most cases, studies were either confounded by time of establishment or treatments were not randomized and lacked independence. We examined aboveground net primary production (ANPP) in northern mixed prairie using a randomized complete block design with four treatments: crested wheatgrass (Agropyron cristatum [L.] Gaertn.), Russian wildrye (Psathyrostachys juncea [Fisch.] Nevski), a native control that was not harvested, and a harvested native. The experiment was conducted in a Stipa–Agropyron–Bouteloua site and a Stipa–Bouteloua site over 13 yr and 12 yr, respectively. The data were analyzed by sampling period (Stipa–Agropyron–Bouteloua: 1, 1994 to 1997; 2, 1998 to 2001; 3, 2002 to 2006; and Stipa–Bouteloua: 1, 1995 to 1998; 2, 1999 to 2002; 3, 2003 to 2006). ANPP among treatments was influenced (P < 0.05) by site and its interaction with treatment and sampling period (1 to 3). ANPP from the native-control, harvested-native, crested wheatgrass, and Russian wildrye treatments was 220.9, 183.9, 300.8, and 189.6 g · m–2 (SEM = 11.2), respectively, in the Stipa–Agropyron–Bouteloua site and 122.9, 98.2, 216.3, and 115.9 g · m–2 (SEM = 12.0), respectively, in the Stipa–Bouteloua site. Mean ANPP (SEM) within each sampling period (1 to 3) was 186.4 (9.1), 135.4 (5.8), and 263.9 (8.8) g · m–2 in the Stipa–Agropyron–Bouteloua site, respectively, and 124.5 (6.4), 138.6 (6.1), and 151.3 (10.5) g · m–2 in the Stipa–Bouteloua site, respectively. Russian wildrye in the Stipa–Bouteloua site and crested wheatgrass in both sites was relatively more productive in the first period after establishment than in subsequent years. The study confirms the relative ANPP advantage of crested wheatgrass over native on the Stipa–Bouteloua site but not on the Stipa–Agropyron–Bouteloua site, whereas Russian wildrye exhibited no ANPP advantage over the native on either site. 相似文献