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母体对小麦胚的ABA敏感性和种子休眠性的影响 总被引:3,自引:0,他引:3
种子休眠是品种穗发芽抗性的主导因素,休眠特性与母体效应和胚对ABA的敏感性均有密切关系。为了了解母体对小麦胚的ABA敏感性和种子休眠的影响,为抗穗发芽育种提供科学依据,对穗发芽抗性不同的小麦品种及它们正反交F1后代授粉后不同发育阶段的胚进行了ABA敏感性鉴定,并对收获前的籽粒发芽能力进行了测定。结果表明,在种子发育过程中,不同基因型的离体胚萌发能力存在差异,抗穗发芽品种的胚对ABA敏感性明显高于易穗发芽品种,胚对ABA的敏感性与其萌发能力关系密切,随着萌发能力的升高,胚对ABA的敏感性降低。在成熟种子中,F1的休眠性偏向于抗性亲本。尽管成熟种子和胚的休眠表现出一定的母体效应,但母体对发育至成熟过程中胚的ABA敏感性并没有影响。因而,母体对种子休眠的影响可能与胚的ABA敏感性无关。 相似文献
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Stem cuttings of peach, nectarine, plum and apricot, obtained from 1-year-old shoots at leaf drop in autumn, were exposed at a constant 3.0 ± 0.1 °C to simulate different chilling accumulation treatments (0, 500, and 1000 chilling hours). A set of 10 excised shoots was forced to budbreak after chilling accumulation; a second set of 10 excised shoots was used to analyse sugars, starch, and ammonium-, nitric- and proteinaceous-nitrogen content in the bark tissues. Sorbitol, fructose and glucose were the main sugars in the bark tissues, whereas sucrose and rafinose showed the lowest quantities in all Prunus sp. studied. Sorbitol and starch concentration decreased whereas glucose and fructose concentration increased with chilling. Ammonium-nitrogen showed the more dramatic increase with medium chilling treatment, decreasing again at high chilling exposure. No modifications in proteinaceous- and nitric-nitrogen levels were observed due to chilling. Chilling treatments increasing flowering intensity showed high ammonium- and proteinaceous-nitrogen content in the bark tissues of the stem cuttings, whereas those reducing flowering intensity showed high starch and nitric-nitrogen content, in three of the four Prunus sp. studied. Ammonium-nitrogen content gives the highest correlation with flowering intensity. 相似文献
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The effect of short day treatments (blackout) on Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) container seedlings at the time of lift and following cold storage was investigated. Variables measured included height, root collar diameter (RCD), root growth capacity (RGC), photosynthetic efficiency after –18 °C freezing (PEF), and days to terminal bud break (DBB). From one to four blackout dormancy induction treatments were started on three dates (July 12, July 26, and August 10) with 10 or 20 d between multiple blackouts. Increasing the number of blackout treatments resulted in lower RCD, lower DBB in the late winter/early spring, and higher PEF in the early fall. Later blackout start dates decreased PEF in the early fall, and increased overall height and late fall RGC as compared to earlier blackout start dates. Nurseries growing Douglas-fir seedlings from coastal Pacific Northwest provenances should be aware that blackout regimes can decrease RGC in the late fall, and cause quicker dormancy release in the early spring. Coastal Douglas-fir can be lifted and planted in the early fall, when RGC and DBB are relatively high. If planting between February and April is necessary, seedlings given blackout should be cold stored in January to maintain an adequate level of dormancy, RGC and PEF. 相似文献
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Changes in carbohydrate, phenols, free amino acids and endogenous hormones in middle scales of Lilium davidii var.unicolor bulbs during the 101 days storage at 2, 6 and 10℃ in moist sawdust were studied. The results indicated that as the storage time increased and the storage temperature delined, contents of starch and abscisic acid (ABA) decreased markedly, and the level of total soluble sugar, phenols, gibberellic acid (GA3) and indole acetic acid (IAA) increased sharply. In the first 34 days, the contents of the above substances changed most actively. Correlation analysis revealed that the increase in content of total soluble sugar and phenols was respectively caused by activation of amylase and phenylalanine ammonia-lyase (PAL). During the storage, the content of free amino acids decreased, and the level of arginine was the highest and changed most remarkably. According to the results of stepwise regression analysis and path analysis, we could primarily conclude that the metabolism of carbohydrates, phenols and free amino acids in the middle scales may be mainly regulated by endogenous GA3. 相似文献
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为了探讨单氰胺对大樱桃萌芽和成熟期的影响,萌芽前,在平度、泰安两地的“红灯”樱桃树上喷洒单氰胺1.5%和2.5%溶液。平度保护地的施药时间为2003年12月24日,泰安保护地和露地的施药时间分别为2004年1月12日和2月10日。试验结果表明,单氰胺能有效促进大樱桃萌芽和开花。平度试验点:经单氰胺处理的樱桃萌芽、开花、成熟期分别比对照提前13d、8d、7d,单果重略小于对照。泰安试验点:经单氰胺处理的萌芽期比对照提前7d,但果实成熟期与对照差异不明显。因此,单氰胺在大樱桃上的作用效果与施药时期有关。 相似文献
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宁夏云雾山典型草原休眠期气候变化对生产力的影响 总被引:1,自引:0,他引:1
基于1992-2011年黄土高原典型草原长期生产力观测数据及相应气候资料,分析了近20a来宁夏云雾山地区休眠期(11月-翌年3月)温度及降水变化趋势,利用简单线性回归及偏最小二乘回归法(Partial Least Squares regression-PLS)探究了休眠期月和日不同尺度温度和降水变化对草地生产力的影响特征,以揭示黄土高原典型草原生产力对休眠期气候变化的响应规律。结果表明:(1)近20a来研究区休眠期平均气温以0.09℃·a-1的速率极显著升高(P<0.01),其中1月和3月升温最为显著(P<0.01);(2)休眠期降水量较少,且年际间变异较大,各月降水变化趋势亦不显著;(3)休眠期内不同阶段温度变化对草地生产力具有不同影响,但整体呈现抑制效应,降水变化对生产力影响不显著;(4)休眠期温度升高抑制草地生产力发展,其作用机制可能与温度升高引起的地表积雪减少、冻融交替频繁及土壤微环境变化有关。休眠期降雨较少,降雨与草地生产力并不存在显著作用关系。降雪作为降水的固态形式,其对生产力的影响特点及作用机制尚待深入探究。 相似文献