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71.
SPAD值与杂交狼尾草施氮水平和农艺性状的关系 总被引:4,自引:2,他引:2
采用盆栽试验探讨利用叶绿素计(Chlorophyll Meter SPAD-502)预测杂交狼尾草粗蛋白含量和牧草的施氮水平.试验设5个氮肥水平(纯氮量0,100,200,300,400k9/hm2)和3次重复,利用叶绿素计读取不同氮水平不同时期杂交狼尾草倒数第3片叶子的SPAD值,同时测定部分农艺性状和茎叶粗蛋白含量.结果表明,杂交狼尾草的SPAD值和粗蛋白含量是随着牧草的生长而逐渐降低,分蘖数、株高和生物产量随着牧草的生长而提高;杂交狼尾草的SPAD值与其施氮水平、分蘖数、株高、产量和茎叶粗蛋白含量都成正相关,与牧草的株高相关性最小且都不显著;与牧草的分蘖数和产量相关性大,接近或达显著水平:与牧草的茎叶粗蛋白含量相关性最大,均达显著或极显著水平.因此,利用SPAD值可用来预测杂交狼尾草茎叶粗蛋白含量,进而诊断杂交狼尾草的氮素营养水平,为牧草的合理施肥提供依据. 相似文献
72.
73.
This study quantified the magnitude of heterosis in pearl millet (Pennisetum glaucum) topcross hybrids produced by crossing 16 diverse landraces and three high yielding open-pollinating varieties on two homozygous
male-sterile lines. Hybrids and pollinators were grown in 12 year ×;location combinations in India that were grouped into
three zones. Genetic components of variance quantifying the differences among these hybrids were estimated. The hybrids showed
a conspicuous heterosis for grain yield, earliness and biomass yield but not for straw yield. The level and direction of heterosis
for time to flowering depended strongly on the earliness of the male-sterile line. In the terminal drought stress zone hybrids
made on the early maturing male-sterile line 843A had the highest level of heterosis for grain yield (88%). This was partly
due to escape from terminal stress. In the other two zones the heterosis for grain yield was on average 30%. Heterosis for
biomass yield and biomass yield per day was on average also positive in all three zones. For all traits, except time to flowering
and biomass yield per day, pollinator effects were the only significant source of variation. Differences between hybrids were
mostly caused by additive genetic effects. Significant amount of heterosis observed in landrace-based topcross hybrids for
grain yield and other productivity-related traits suggested that substantial improvement in pearl millet productivity in and
environments can be obtained by topcrossing locally adapted landraces on suitable male-sterile lines.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
74.
Inter‐population hybrids of pearl millet, Pennisetum glaucum (L.) R. Br., have a substantial grain yield advantage over open‐pollinated varieties that makes them an appropriate and economically viable proposition for many African agricultural situations, provided that stable male‐sterile populations can be developed for use as seed parents. The objective of this research was to examine the feasibility of breeding stable male‐sterile populations, using the d2 dwarf version of Nigerian Composite NCD2 and the A4 cytoplasmic‐nuclear male sterility system as a test case. Results showed that two cycles of recurrent selection for sterility maintenance ability led to the development of a fully effective maintainer version of NCD2. There was no significant difference between the original C0 cycle bulk and the C3 cycle bulk (developed from the third and final cycle of recurrent selection) for grain yield and other agronomic traits. The male‐sterile population at the third backcross stage, developed from the maintainer version of NCD2, had as high a level of stable male sterility as the A1 system commercial inbred male‐sterile line 841A1. Thus, it is concluded that with the use of the A4 cytoplasmic male‐sterile system, it would be possible rapidly to develop a maintainer version of any population without detrimental effects on grain yield and agronomic traits. Male sterility of populations developed from these maintainers will be highly stable, paving the way for their effective utilization as seed parents in breeding inter‐population hybrids. 相似文献
75.
76.
美洲狼尾草Tift23A(Pennisetumamercunum以下简称23A)在适宜播期内主茎叶数一般为25。出叶间隔2~4d。出叶速度总体上依抽出顺序而温慢,其分蘖一期发生在5~7叶龄;拔节则发生在14叶龄前后,幼穗分化与拔节基本同步,在杂交制种中,当母本23A拔节前对父本象草N51(P.purpureum,以下简称N51)进行3~4周,每日9h的短日照处理,则父母本花期基本相遇。 相似文献
77.
Different indices for selection of lines grown under low and high water levels were examined from both theoretical and practical standpoints. Pearl millet ( Pennisetum americanum (L.) K. Schum) was planted under a sprinkler irrigation gradient in 1983 and 1984. Equations were developed for drought tolerance for both yield and forage production. Correlation coefficients were developed for yield and yield components.
The equations showed that drought will generally result in decreased productivity of both grain and forage. Grain yield was found to be positively correlated with seed weight and with the number of seeds in the main head, and negatively correlated with plant height under low water level. Dry matter was positively correlated with tiller number. 相似文献
The equations showed that drought will generally result in decreased productivity of both grain and forage. Grain yield was found to be positively correlated with seed weight and with the number of seeds in the main head, and negatively correlated with plant height under low water level. Dry matter was positively correlated with tiller number. 相似文献
78.
研究了不同越冬措施对矮象草生长状况和生产性能的影响。结果表明:相对于覆草、盖土和对照,覆膜措施更能有效提高矮象草的返青率、鲜草产量和品质;茎粗和单株叶片数是预测鲜草产量的主要指标,与鲜草产量呈正相关关系。 相似文献
79.
以象草种茎为材料,利用10、20和30 Gy剂量的60Co-γ射线照射种茎,筛选适宜诱变剂量并研究其表型性状变异和分子水平上的遗传变异,为象草辐射诱变育种提供理论和技术基础。结果表明,辐射处理后的植株有矮化的趋势,其中分蘖数、茎节数和叶长对辐射最敏感,容易发生变异;在所有诱变系材料中,F30-39和F30-41聚为一类,与对照材料差异最大,是显著矮小化的植株。30 Gy诱变系与未辐射的材料间的遗传相似系数在0.3793~0.9655,平均为0.8276,而差异位点数在4~66个,平均为19.3个,两项指标均大于10和20 Gy诱变系群体。综合考虑辐射后植株存活率与遗传变异结果,选定30 Gy为最适宜的象草种茎辐射诱变剂量。 相似文献
80.