驱蚊香草的组织培养和快速繁殖   总被引：4，自引：0，他引：4  

江新国  刘杏泉 《江西林业科技》2004,(5):19-19,21

以驱蚊香草幼嫩枝条为外植体，进行离体培养，获得再生植株，通过这个过程，得出有利于芽诱导、增殖、诱导生根的最佳配方，为驱蚊香草快速繁殖，规模化生产打下技术基础。  相似文献   

磷素环境与马褂木种源的生长和干物质积累   总被引：5，自引：0，他引：5  

李建民  王剑  周志春  饶龙兵  金国庆 《林业科学》2005,41(5):192-195

自然土壤中有效磷含量很低,难以满足植物最佳生长的需要。据统计,在全世界13·19亿hm2的耕地中约有43%缺磷,而我国耕地则有2/3缺磷(何绪生等,1998)。我国南方地区高温多雨,富铝化作用明显,多数土壤呈酸性或强酸性,磷素固定强烈,土壤有效磷含量仅在1~2mg·kg-1(邱燕等,2003)。虽然施用磷肥的效果显著,但其利用率一般不超过10%,多为土壤固定并转变成植物较难吸收的Ca-P、Fe-P和Al-P等(熊毅,1997)。鉴于植物具有将土壤难溶态磷转化为有效态磷并加以吸收利用的能力,通过选育磷高效利用的植物品种来开发土壤中难溶态的磷素资源,可减小对施用磷…  相似文献   

Investigations on the antinociceptive activity of crude extracts from Croton cajucara leaves in mice     

Campos AR  Albuquerque FA  Rao VS  Maciel MA  Pinto AC 《Fitoterapia》2002,73(2):116-120

The crude leaf extracts of Croton cajucara Benth. were studied for their antinociceptive property in chemical and thermal models of nociception in mice. All the tested extracts (hexanic, chloroformic and methanolic), at oral doses of 100 and 200 mg/kg demonstrated significant inhibition of acetic acid-induced writhing and the second phase response of formalin, but did not manifest a significant effect in hot-plate test.  相似文献   

A study of the potential of hedgerow intercropping in semi-arid India using a two-way systematic design     

M. R. Rao  M. M. Sharma  C. K. Ong 《Agroforestry Systems》1990,11(3):243-258

The potential of hedgerow intecrropping with Leucaena leucocephala was explored on vertic Inceptisols over 4 years at ICRISAT Center, Patancheru, India. The study was conducted using a systematic layout involving different alley widths ranging from 1.35 to 4.95 m and with varying distances between hedge and crops. The alleys were cropped with alternate rows of sorghum and pigeonpea. Hedges composed double Leucaena hedgerows 60 cm apart were periodically harvested for fodder. Sole crops of all components and a sorghum/pigeonpea intercrop were included in all four replications of the study.Starting in the second year, Leucaena was progressively more competitive to annual crops, causing substantial yield reduction. Competition (primarily for moisture) was most severe in narrow alleys and was greatest on pigeonpea.The growth of Leucaena was not sufficient to compensate for reduced crop yields. Land equivalent ratios (LERs) calculated on the basis of grain yield of crops and Leucaena fodder yields showed that hedgerow intercropping (HI) was advantageous over sole crops only during the first two years using wide alleys, but disadvantegeous in the last two years. LERs calculated on the basis of total dry matter indicated only a small advantage for HI (13–17 percent) over sole crops in wider (>4 m) alleys. Average returns per year from HI exceeded those of the most productive annual crop system (sorghum/pigeonpea intercropping) by 8 percent in 4.05 m alleys, and by 16 percent in 4.95 m alleys. Fodder production during the dry season was 40 percent of the annual total in these alley widths. Thus hedgerow intercropping at 4–5 m alley width is not very attractive for farmers in semi-arid India, which has 600–700 mm of annual rainfall. There is a need to examine the potential of HI in wider alleys. The merits and limitations of the systematic design are discussed.  相似文献   

Inheritance and cross-resistance of <Emphasis Type="Italic">Bacillus thuringiensis</Emphasis> insecticidal crystal protein Cry1Ac resistance in cotton bollworm <Emphasis Type="Italic">Helicoverpa armigera</Emphasis> Hubner population from Tamil Nadu,India     

P. S. Shanmugam  R. Balagurunathan  N. Sathiah  N. G. V. Rao 《Journal of pest science》2007,80(3):175-181

Cotton bollworm, Helicoverpa armigera Hubner selected for five generations with Bacillus thuringiensis insecticidal crystal protein Cry1Ac in the laboratory developed 12.98-fold resistance. Resistance and susceptible populations were mass crossed to study the dominance of resistance. The Cry1Ac—selected (BCR) population showed 5.8-fold resistance to Cry1Aa and 5.04-fold resistance to Cry1Ab. The degree of dominance (D) was 0.34 and 0.40 for the R × S and S × R hybrids, respectively, which indicates incomplete recessive character of Cry1Ac resistance in the population. The estimated realized heritability (h ²) and response quotient (Q) of resistance for Cry1Ac were 0.52 and 0.15, respectively. This indicated the lower phenotypic variation in the selected population. The resistance risk assessment based on h ² indicated that the resistance would increased tenfold after <9 generations for Cry1Ac in the resistant population. The results show the ability of H. armigera to develop resistance against Cry1Ac and cross-resistance to Cry1Aa and Cry1Ab.  相似文献   

Medicinal and aromatic plants in agroforestry systems     

Rao  M.R.  Palada  M.C.  Becker  B.N. 《Agroforestry Systems》2004,61(1-3):107-122

Agroforestry Systems - A large number of people in developing countries have traditionally depended on products derived from plants, especially from forests, for curing human and livestock...  相似文献   

Crop productivity under differently lopped canopies of multipurpose trees in Central Himalaya, India   总被引：3，自引：1，他引：3  

R.L. Semwal  R.K. Maikhuri  K.S. Rao  K. Singh  K.G. Saxena 《Agroforestry Systems》2002,56(1):57-63

Ficus species are multipurpose trees well known by rural populations in Sahelian and Sudanian zones of Africa. Their uses are well documented but their amenability for vegetative propagation has not been extensively studied. This paper compares the rooting ability of stem and aerial root cuttings from thirteen Ficus species found in West Africa. It highlights the differences between species belonging to the sub-genera Sycomorus and Urostigma. The former show no capacity to propagate from cuttings whereas the latter, with epiphytic development, can be propagated by cuttings, although this capacity varies among species. Thus, F. thonningii, F. leprieurii and F. ovata are easily propagated, while F. platyphylla and F. elasticoides are propagated with difficulty. The rooting capacity also varies depending on the cutting material used. It decreases in the following order: long leafless hardwood cuttings (pole) > nodal cuttings > apical cuttings. Rooting potential increases when the cuttings are harvested towards the end of the dry season(March to May). Aerial root can be used for cuttings in all species of the sub-genus Urostigma. The capacity of root cuttings to regenerate is greatest when cuttings are collected at the beginning of the dry season (November). In this case, wound-induced adventitious roots arise at the basal end of the cutting while de novo buds are developed from the cambium at the distal end. The subsequent morphological development is identical to that of a stem cutting. These results clarify and allow the optimal use of the knowledge and methods developed by the indigenous people of the Sahel and could assist and promote fig tree (Ficus sp.) domestication in the dry tropics.This revised version was published online in November 2005 with corrections to the Cover Date.  相似文献   

厚朴矮林经营技术的初步研究     

刘日林  叶春林  斯金平  刘饶  周建清 《浙江林业科技》2002,22(2):29-31

厚朴伐桩有很强的萌蘖能力，在生长季节采伐也能得到满意的萌芽更新效果，每个伐桩可萌发1－7个萌芽条，7年生厚朴矮林的树干与树枝鲜重达60.2t.hm^-2，平均净生产量为8.6t.hm^-2.a^-1，表明厚朴完全适宜矮林经营，伐桩高度对萌芽条数量，矮林生长影响不大；伐桩萌芽条数量越多，矮林生长越好。  相似文献   

A new phorbol diester from Aleurites moluccana     

Satyanarayana P  Kumar KA  Singh SK  Rao GN 《Fitoterapia》2001,72(3):304-306

A new phorbol diester, 13-O-myristyl-20-O-acetyl-12-deoxyphorbol (1), has been isolated from the benzene extract of the heartwood of Aleurites moluccana. In addition, hentriacontane, 6,7-dimethoxycoumarin, 5,6,7-trimethoxycoumarin and beta-sitostenone are being reported for the first time from this species.  相似文献   

The gene expression pattern induced by high plating density in cultured bovine and buffalo granulosa cells might be regulated by specific miRNA species     

Vengala Rao YENUGANTI  Vijay Simha BADDELA  Anja BAUFELD  Dheer SINGH  Jens VANSELOW 《The Journal of reproduction and development》2015,61(2):154-160

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