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排序方式: 共有30条查询结果,搜索用时 46 毫秒
1.
柑桔园生草栽培的生态效应研究   总被引:11,自引:0,他引:11  
柑桔园生草栽培的生态效应研究李国怀章文才刘继红胡德文(华中农业大学园艺系,武汉430070)StudiesofEcologicalEfectsofSodCultureinCitrusOrchard.LiGuohuai,ZhangWencai,LiuJ...  相似文献
2.
武夷山不同海拔土壤呼吸及其主要调控因子   总被引:5,自引:0,他引:5       下载免费PDF全文
2005年4月-2006年3月,选择福建武夷山不同海拔高度上的常绿阔叶林、针叶林、亚高山矮林和高山草甸4个不同的群落作为实验地,每月测量1次土壤呼吸,测定影响土壤呼吸变化的土壤生物与非生物因子(包括土壤温度,土壤湿度,土壤有机碳、氮、硫含量,凋落物量,微生物量以及细根生物量等),研究了土壤呼吸的空间异质性.结果表明:随着海拔的升高,年均土壤呼吸速率显著降低,而土壤碳、氮、硫含量,土壤微生物量以及细根生物量等却增大;常绿阔叶林土壤呼吸速率是高山草甸的1.82倍;土壤呼吸的空间变化只与土壤温度呈显著的相关性;证明在影响土壤呼吸的土壤因子中,土壤温度是调控其在海拔高度上变化的主导因子.  相似文献
3.
为保护热带雨林,改变现有砂仁栽培模式,探讨改雨林下种砂仁为次生林下种砂仁的可行性.比较研究了热带雨林和次生林下砂仁的生长状况和产量.砂仁种植对雨林生物量和生产力影响显著,对次生林的影响不显著.2种林下砂仁4类植株的密度和生物量的大小顺序均为壮株、衰老株、苗和笋.雨林和次生林下砂仁笋和苗的总数分别为衰老株数量的3.95和1.66倍,远多于衰老株数量,表明砂仁能够维持种群稳定.雨林下砂仁苗多为长势较弱的老苗,绝大多数最终不能生长成壮株.2种林下砂仁壮株密度和生物量差异不显著。但次生林下砂仁衰老株、苗和笋的密度和生物量显著高于雨林,表明次生林下砂仁更新比雨林下快.次生林下砂仁产量为78.068kg·hm^-2,略高于雨林.值得注意的是。砂仁产量很低,茎生物量比很高(0.6以上),果实生物量比极低(0.01),增产潜力较大.次生林的生物量低于雨林,透光率高于雨林。土壤水分含量与雨林接近,有利于砂仁的生长发育。可以在次生林下种植砂仁。  相似文献
4.
The potential of chitosan, a non-toxic and biodegradable polymer of beta -1,4-glucosamine, for controlling fusarium crown and root rot of greenhouse-grown tomato caused by Fusarium oxysporum f.sp. radicis-lycopersici (FORL) was investigated. The amendment of plant growth substratum with chitosan at concentrations of 12.5 or 37.5 mg l-1 significantly reduced plant mortality, root rot symptoms and yield loss attributed to FORL. Maximum disease control was achieved with chitosan at 37.5 mg l-1, when plant mortality was reduced by more than 90% and fruit yield was comparable with that of non-infected plants. In the absence of FORL, chitosan did not adversely affect plant growth and fruit yield. Cytological observations on root samples from FORL-inoculated plants revealed that the beneficial effect of chitosan in reducing disease was associated with increased plant resistance to fungal colonization. In chitosan-treated plants, fungal growth was restricted to the epidermis and the cortex. Invading hyphae showed marked cellular disorganization, characterized by increased vacuolation and even complete loss of the protoplast. The main host reactions included the formation of structural barriers at sites of attempted fungal penetration, the deposition of an opaque material (probably enriched with phenolics according to its electron density) in intercellular spaces and the occlusion of xylem vessels with tyloses, polymorphic bubbles and osmiophilic substances. Although chitosan may also have antifungal properties, the ultrastructural observations provide evidence that chitosan sensitizes tomato plants to respond more rapidly and efficiently to FORL attack. Chitosan has the potential to become a useful agent for controlling greenhouse diseases caused by soil-borne pathogens.  相似文献
5.
西双版纳阳春砂仁栽培的两种模式的比较研究   总被引:4,自引:0,他引:4       下载免费PDF全文
 阳春砂仁(Amomum villosum)种植对热带湿性季节雨林的影响十分显著,对次生林的影响不大。为保护热带雨林,改变现有阳春砂仁栽培模式,探讨雨林下种阳春砂仁改为次生林下种植阳春砂仁的可行性,比较研究了热带雨林和次生林下阳春砂仁的生长状况和产量。次生林和雨林林下阳春砂仁壮株密度和生物量均明显高于其它株型,同类型林下阳春砂仁笋、苗和衰老株密度差异不显著,但衰老株生物量显著高于笋和苗。次生林和雨林下阳春砂仁笋和苗的密度之和分别为衰老株的1.45和2.18倍,远多于衰老株数量。表明阳春砂仁种群能够维持稳定。值得注意的是阳春砂仁产量很低,茎生物量比很高(0.58以上),果实生物量比极低(约0.01),增产潜力较大。在水分较充足的一块次生林样地阳春砂仁果实产量高达211.149 0 kg•hm-2,远高于其它样地。阳春砂仁喜湿可能与其较低的根生物量比和浅根系有关。阳春砂仁叶面积指数、壮株和全部植株生物量与果实产量呈极显著的正相关。次生林和雨林林下阳春砂仁生物量、产量叶面积指数和各株型密度差异均不显著。研究结果表明次生林下可以种植阳春砂仁。  相似文献
6.
Introgression of spontaneous or induced mutations has been used to increase the levels and diversify the profile of antioxidants in many fruits including tomato. The high-pigment (hp) and old-gold (og) alleles exemplify this approach as attractive genetic resources suitable to inbred elite high-lycopene (HLY) tomato lines with improved color and nutritional attributes. Although several studies have been published on HLY tomatoes, a systematic analysis of the information on their agronomic performances, processing features, and functional quality is lacking, leaving room for the assumption of their poor competitiveness with conventional tomato cultivars and limiting their agricultural diffusion. Therefore, the aim of this study is to critically review the most important agronomic, horticultural, and functional traits of HLY tomatoes, as well as the advances in some emerging (pre)industrial applications. Field experiments performed in different countries showed that most available HLY lines are productive, vigorous, with excellent foliage cover and with morphologically acceptable fruit. Tomato yield of HLY genotypes ranged from ~30 to ~178 t/ha exceeding, in some trials, that of highly productive cultivars. Red-ripe fruits of most HLY lines showed commercially suitable soluble solids and titratable acidity, in addition to increased levels of lycopene (up to 440 mg/kg fw) and other bioactive phytochemicals (mainly flavonoids and vitamin C) compared to their near isogenic conventional counterparts. Innovative (pre)industrial uses of HLY tomato include the following: (1) production of HLY sauces, juices, and powders; (2) supercritical-CO2 extraction of lycopene containing oleoresins; and (3) preparation of lycopene rich micro- and nano-carriers with improved stability and specific tissue delivery. In turn, the use of these innovative high-quality ingredients in the formulation of lycopene fortified foods, cosmetic products, nutraceuticals, and pharmaceuticals has been proposed as the basis of a novel highly profitable tomato product chain.  相似文献
7.
刘琼霞  文礼章  周华建  吴倩  肖治术 《昆虫学报》2011,54(10):1133-1139
黄连木Pistacia chinensis Bunge因果实含油量高, 被作为生物能源树种在我国进行大面积栽培推广和能源开发利用。然而, 专性寄生害虫(主要为黄连木广肩小蜂Eurytoma plotnikovi Nikolskaya)的危害及由单性结实和败育所造成的空壳果实可能影响黄连木的果实产量和质量。为了评价种子害虫和空壳果实对黄连木果实产量和质量的影响, 我们测定了河南省济源市3个黄连木种群40株结果雌树的果实产量和油产量, 同时测定了完好果实、 空壳果实和虫蛀果实等3类果实的干重和含油量。结果表明:(1)虫害率和空壳率分别达22.6%和53.0%, 且不同个体和种群间均存在显著差异(P<0.05)。(2)空壳果实(30.7 mg/果)和虫蛀果实(33.1 mg/果)的干重均不到完好果实(67.4 mg/果)的一半; 空壳果实(3.9%)和虫蛀果实(3.8%)的含油量均显著低于完好果实(39.9%)。(3)实测的果实产量(2.9 kg/树)和油产量(0.6 kg/树)分别仅为期望产量的50%(4.7 kg/树)和33%(1.9 kg/树), 但在3个种群之间无显著差异。本研究显示小蜂危害和空壳果实对黄连木果实产量和质量能造成严重影响, 在将其作为生物能源树种利用时对此应加以克服。  相似文献
8.
The localized application of the synthetic cytokinin CPPU ((2-chloro-4-pyridyl)-N-phenyl urea) to ovaries at flower opening was as effective as free pollination in setting parthenocarpic fruit in the triploid watermelon cultivar ‘Reina de Corazones’, and increased yield per unit land area by at least 50%, simply due to the lack of requirement for diploid pollen producing plants within the orchard. The application of the synthetic auxin 2,4-D (2,4-dichlorophenoxy acetic acid) as a full coverage spray, was also effective in setting fruit; total yield was however 10% smaller than in the CPPU-treated plots, but the cost of application was much less expensive. These applications had no adverse effect on fruit quality, and their effectiveness in commercial watermelon production was evaluated over 4 years. Localized applications of 2,4-D to ovaries were less effective in setting fruit, and increased hollow fruit.  相似文献
9.
Important agronomic traits such as fruit quality, harvesting efficiency or production largely depend on flowering time. We have analysed the effect of the overexpression of the Arabidopsis APETALA1 MADS-box gene on vegetative and reproductive growth of tomato. Constitutive expression of APETALA1 in tomato plants has major effects on the length of their growth cycle as well as on their growth habit. Transgenic tomato plants initiated flowering after the production of 6 vegetative nodes as compared to 11 nodes for the wild type plants. Most of tomato 35S:AP1 plants also showed determinate growth habit, similar to the phenotype of self pruning tomato mutants, as well as an initial reduction of their axillary growth. Moreover, development and fertility of flowers were not affected in plants expressing AP1. Consequently, fruit formation in transgenic plants grown under greenhouse conditions occurred normally, which permitted a similar fruit yield compared to control plants. Since traits conferred by AP1 expression are dominant, its expression in tomato breeding lines could provide advantages for the development of new hybrid varieties with shorter generation time, determinate growth, and reduced pruning requirements.  相似文献
10.
示范试验结果表明,成年龙眼的平衡施肥对提高土壤肥力、保持树体适宜营养水平以及增加果实产量有明显作用,从而证实平衡施肥方案的可行性。作者推荐,闽南丘陵地成年龙眼园的年施肥方案(667m2,产果1吨):N20~25kg(有机肥的N约占年施N量的40%);N:P2O5:K2O:CaO:MgO=1.0:0.5~0.6:1.0~1.1:0.8:0.4。  相似文献
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