排序方式： 共有16条查询结果，搜索用时 31 毫秒
1.
2.
3.
The incidence–severity relationship for cashew gummosis, caused by Lasiodiplodia theobromae , was studied to determine the feasibility of using disease incidence to estimate indirectly disease severity in order to establish the potential damage caused by this disease in semiarid north-eastern Brazil. Epidemics were monitored in two cashew orchards, from 1995 to 1998 in an experimental field composed of 28 dwarf clones, and from 2000 to 2002 in a commercial orchard of a single clone. The two sites were located 10 km from each other. Logarithmic transformation achieved the best linear adjustment of incidence and severity data as determined by coefficients of determination for place, age and pooled data. A very high correlation between incidence and severity was found in both fields, with different disease pressures, different cashew genotypes, different ages and at several epidemic stages. Thus, the easily assessed gummosis incidence could be used to estimate gummosis severity levels. 相似文献
4.
5.
During March and April of 1993 and 1994, surveys on the incidence and severity of cashew powdery mildew ( Oidium anacardii ) were conducted in the Newala, Mtwara, Nachingwea and Tunduru areas of southern Tanzania to determine the variation in perennation between localities. Only immature cashew shoots, panicles and fruit can be infected by O. anacardii conidia. Cashew trees at sites in each district were assessed for shoot and panicle production and cashew powdery mildew. Survival of O. anacardii between seasons, in any area, was determined by the degree of production of shoots that were within the canopy and by the incidence of infection. Immature shoots produced from the main branches within the tree canopy were the main source of active powdery mildew in all districts; trees in the Newala district had the highest numbers of infected immature shoots in comparison with survey sites in the other areas. During the 1994 cashew-growing season (June–August), powdery mildew developed more rapidly and affected more shoots on the inside of the tree canopy than on the outside. Germination of conidia was reduced after aqueous suspension for 3 h. Germination on cashew leaves submerged under 2 mm of water was not affected. Appressorial and hyphal formation by germinating conidia on leaves decreased with increasing duration under water. Germination of conidia on glass slides at 100% r.h. was higher at 25 and 30°C than at 15°C and there was no germination at 35°C. 相似文献
6.
利用RAPD技术,对75份国内现有的腰果种质资源进行遗传亲缘关系及分类研究。利用45个随机引物对75份腰果种质资源的基因组DNA进行PCR扩增,共扩增出407条谱带,其中多态性谱带为294条,多态率达72.24%,表明75份腰果种质资源具有丰富的多态性。75份国内现有的腰果种质遗传相似性分析结果表明,各种质资源间的遗传相似系数在0.690~0.936之间,平均相似系数为0.841;通过UPGMA法建立了75份腰果种质资源的亲缘关系聚类图,当D=0.79时,将75份腰果种质划分成16个类群。分析结果表明多数来源相同的种质资源表现出较为密切的亲缘关系。 相似文献
7.
M. A. Faluyi 《Plant Breeding》1986,97(3):237-245
Seedlings from 27 open pollinated cas-hew genotypes in two environments with five replications in each location were used to investigate the genetic, the environmental, and the nut size effects on cashew seedling vigour during the 12-week pretransplantation period. Enviromental variances, genotype × environment interactions, and broadsense heritability values for the eight studied traits indicated that emergence percentage (L %) and seedling height (SH) were more reliable indices for seedling vigour, since they were more heritable and less influenced by the environment. Seedlings from large cashew nuts were consistently more vigorous than those from small nuts, probably because of the larger food reserve in the two cotyledons. 相似文献
8.
腰果种子发芽率的快速测定方法 总被引：5，自引：0，他引：5
比较了4种快速测定腰果(Anacardium occidentale L)种子发芽率方法的准确性。结果表明：对不同贮藏时间的腰果种子，TTC染色法的测定结果准确可靠，检出率与发芽率相同，是快速测定腰果新鲜度的有效方法；外观和品尝法的鉴定结果准确度低，误差较大；电导率的测定需时短，简捷快速，准确性受标准参照物的影响；红墨水染色法虽不需设备和特殊药品，但结果与发芽率相比较，有一定差异。 相似文献
9.
Comparative analysis of powdery mildew development on leaves, seedlings and flower panicles of different genotypes of cashew 总被引：2，自引：0，他引：2
Resistance of cashew ( Anacardium occidentale ) genotypes to powdery mildew ( Oidium anacardii ) was assessed on detached leaves, seedlings and flower panicles. Leaves were more susceptible before the development of a waxy cuticle, which confers a dull appearance. Differences in susceptibility/resistance were observed on detached leaves inoculated in the laboratory. Some genotypes supported dense growth of mildew, whereas on others only slight infection was observed under comparable conditions. Mature leaves were immune to colonization. In the field the rate of mildew infection, as estimated from disease progress curves on both seedlings and flower panicles, varied significantly between genotypes allowing their categorization into susceptible and partially resistant clones. A similar rank order for degree of susceptibility/resistance was determined from studies on detached leaves, seedlings and flower panicles. Brazilian introductions of A. occidentale and the AZA2 and AC6 genotypes proved to be partially resistant, while AM6, ATA19 and AIN62 were highly susceptible. The relationship between leaf and flower mildew infection showed positive and highly significant correlations. It is concluded that each of the three approaches to the assessment of disease susceptibility can be used to screen genotypes against mildew attack. Screening in the laboratory provides a rapid indication of potential resistance providing that leaves are compared at the same stages of maturity. 相似文献
10.
《Communications in Soil Science and Plant Analysis》2012,43(8):679-688
Abstract The nutrition of cashew (Anacardium occidentale L.), commercially grown on a large scale on infertile sandy Spodosols at Besut, Malaysia, was evaluated based on the major element of the leaves composition from two fertilizer trials and from an independent field nutritional survey (1979–1981). Except for the sampling periods which represented four physiological stages of the crop, commercial fertilizers applied even up to 1.4 kg/ tree/year did not show significant changes in the five major elements in cashew tree leaves. However, the organic matter levels within the top 32 cm of the surface soil did show consistent positive correlations with each of the five major elements in leaves sampled from a nutritional survey. The significance of these foliar data is discussed in relation to the overall nutrition of cashew grown extensively on sandy infertile soils of Malaysia. 相似文献