首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   32篇
  免费   0篇
林业   1篇
农学   5篇
  6篇
综合类   2篇
农作物   1篇
水产渔业   12篇
畜牧兽医   1篇
园艺   1篇
植物保护   3篇
  2022年   2篇
  2021年   2篇
  2019年   1篇
  2018年   3篇
  2016年   2篇
  2015年   1篇
  2014年   1篇
  2013年   7篇
  2012年   1篇
  2011年   2篇
  2010年   2篇
  2007年   2篇
  2005年   1篇
  2004年   3篇
  2003年   1篇
  1990年   1篇
排序方式: 共有32条查询结果,搜索用时 62 毫秒
1.
Summary Studies on genetic diversity in chickpea (Cicer arietinum L.) indicated the existence of considerable amount of variation for grain yield and its components in the material. One hundred and thirty two genotypes fell into eight clusters. The covariation structure studied by means of factor analysis indicated the possibility of obtaining, through hybridization, genotypes physiologically and morphologically more efficient. Multivariate analysis of data from 7 parents and 21 F1 hybrids indicated weak correspondence between D2-analysis and canonical variate analysis. As there was no relationship between heterosis over midparent and genetic distance between the parents, so the traditional approach of making a large number of crosses is being suggested.  相似文献   
2.
M. Imtiaz    M. Ahmad    M. G. Cromey    W. B. Griffin  J. G. Hampton 《Plant Breeding》2004,123(5):401-404
Stripe rust of wheat caused by Puccinia striiformis West. f. sp. tritici presents a serious problem for wheat production worldwide, and identification and deployment of resistance sources to it are key objectives for many wheat breeders. Here we report the detection of simple sequence repeat (SSR) markers linked to the durable adult plant resistance of cv. ‘Otane’, which has conferred this resistance since its release in New Zealand in 1984. A double haploid population from a cross between ‘Otane’ and the susceptible cv. Tiritea’ was visually assessed for adult plant infection types (IT) in the glasshouse and field, and for final disease severity in the field against stripe rust pathotype 106E139A+. At least three resistance loci controlled adult plant resistance to stripe rust in this population. Quantitative trait loci (QTL) mapping results revealed that two of these, one on chromosome 7DS corresponds to the durable adult plant resistance gene Yr18 and other on chromosome 5DL were contributed from ‘Otane’; while the remaining one on chromosome 7BL, was contributed from the susceptible ‘Tiritea’. Interval mapping placed the ‘Otane’‐resistant segment near the centromere of chromosome 7DS at a distance of 7 cM from the SSR marker gwm44. The stability of QTL in the two environments is discussed. SSR gwm44 is potentially a candidate marker for identifying the durable resistance gene Yr18 in breeding programmes.  相似文献   
3.
Relations between nitrogen (N) nutrition and salinity tolerance in plants are multifaceted and varies significantly depending on many soil and plant factors. Saline environment might experience an N dilemma due to the opposing effects of salt ions on N uptake, translocation and metabolism within the plant body. Adequate regulation of N under saline conditions can be a promising approach to alleviate salinity’s effects on plants by ameliorating ion toxicity and nutrient imbalances through its impacts on the uptake and redistribution of salt ions within the plant. Certain N-containing compounds including proline, glycine betaine, proteins and polyamines help the plants to tolerate salinity through their involvement in improving water uptake and water use efficiency, membrane integrity, enzyme activation, hormonal balance, chlorophyll synthesis, stimulation of photosystems and CO2 assimilation under salinity stress. Nitrogen, particularly NO3? represents a stress signal that triggers the activation of antioxidant enzymes to protect the plants against salinity-induced oxidative damage. Furthermore, the source/form of N application can affect not only N-interactions but also the behavior of other nutrients in stress environment. The present review deals with N-salinity relations in plants, particularly glycophytes, emphasizing on N-induced mechanisms which can improve plant adaptation to saline environment.  相似文献   
4.
A number of improved cultivars of food legume crops have been developed and released in the tropics and the sub-tropics. Most of these cultivars have been developed through conventional breeding approaches based on the development of crop varieties under optimum soil fertility levels. Nevertheless, it is hardly possible to say that the varietal provisions made by the past approach have been readily accepted, and properly utilized to boost productivity of food legumes grown by resource-poor farmers. The approach itself did not fully appreciate the actual circumstances of the resource-poor farmers where marginal production systems prevail and the poorest farmers could not afford to use cultivars developed under optimum soil fertility level. Therefore, the limitations and strategic implications of past experiences made to develop crop cultivars need to be analyzed in order to formulate better strategies and approaches in the future. The main purpose of this article is to review the efforts made, the technical difficulties associated with the genetic improvement in food legumes as related to plant-nutrient relations, causes of limited breeding success and thereby draw lessons useful to designing future breeding strategies. The scope of nutrient deficiency stress and the approaches to breeding for plant-nutrient relations are discussed and the need for refining the approach and better targeting of the breeding methodologies suggested.  相似文献   
5.
Abstract

Inoculation effect of arbuscular mycorrhizal fungi (AMF) on phosphorus (P) transfer from composted dung of cattle with a diet supplemented with powdered rock phosphate (RP) and their successive uptake by mung bean plants was assessed in alkaline soil. The efficacy of composted RP fed dung alone or/and in combination with AMF inoculums containing six different species were compared with SSP in six replicates per treatment in pots. The results showed that the association of AMF with composted RP fed dung had a positive effect on mung bean shoot (3.04?g) and root (2.62?g) biomass, chlorophyll (a, b), carotenoid contents and N (58.38?mg plant?1) and P (4.61?mg plant?1) uptake. Similarly, the percent roots colonization (56%) and nodulation of mung bean plant roots and their post-harvest soil properties were also improved by the inoculation of AMF together with composted RP fed dung. It is concluded that the combined application of AMF with composted RP fed dung has almost the same effect as SSP for improving mung bean plants growth and their nutrients uptake. Moreover, AMF inoculants can be used as a suitable biofertilizer in combination with locally available organic sources of fertilizers for improving P status and growth of plants in alkaline soils.  相似文献   
6.

Field experiments were conducted on wheat during 2017–2018 and 2018–2019 under rainfed conditions. The statistical significance between treatment means was determined at 5% significance level. Data were recorded on weed density, protein, fat and ash contents of wheat grains. Weed density in shallow tillage was highest (20.67?m?2) while it was lowest (14.23?m?2) in deep tillage. In weed control factor, weed density was highest in weedy check (33.10?m?2), followed by parthenium aqueous extract (21.50?m?2), and lowest (6.79?m?2) in plots treated with Affinity (isoproturon?+?carfentrazone). Results showed that the highest crude protein content (10.88%) was recorded in deep tillage, while lowest (10.45%) in shallow tillage, indicating that tillage depths have an impact on wheat grains protein content. For weed control factor, the crude protein content was highest (11.98%) in Affinity treated plots, followed by herbicides, Buctril super (bromoxynil?+?MCPA) (11.44%) and Puma super (fenoxaprop-p-ethyl) (11.12%). Hence, the control measures also affected crude protein content of wheat grains, which is also obvious from the weedy check where wheat grains crude protein content was lowest (9.73%). The two years combined data analysis also showed the highest crude fat content (1.75%) in deep tillage treatments followed by normal tillage (1.67%) and lowest fat content (1.53%) in shallow tillage. For ash content, the highest content (3.03%) was with Affinity herbicide treatments, followed by Buctril super (2.74%) and Puma super (2.48%) herbicides. In conclusion, both the tillage and herbicides indicated positive effects on the nutritive status of wheat grains.

  相似文献   
7.
This study investigated the influence of Bacillus‐based probiotics on performance and intestinal health in broiler challenged with Clostridium perfringens‐induced necrotic enteritis. One‐day‐old Arbor Acre (n = 480) were randomly assigned to four treatments with 10 cages of 12 birds: (a) basal diet negative control (NC), with no probiotics nor antibiotics formulated to contain 2,930 and 3,060 kcal/kg with 24.07 and 15.98% CP, for starter and finisher diet, respectively, (b) basal diet + enramycin (5 mg/kg), an antibiotic growth promoter (AGP); (c) basal diet + Bacillus subtilis B21 at 2 × 109 CFU per g (BS); (d) basal diet + Bacillus licheniformis B26 at 2 × 109 CFU per g (BL); growth performance, intestinal morphology, intestinal lesion scores, short‐chain fatty acids (SCFAs) and mucosal barrier tight junction's (TJ) mRNA expression were assessed. NC‐ and BL‐fed groups showed higher (p = 0.005) average daily feed intake from d1 to d21 than AGP and BS, whereas BS‐ and AGP‐fed groups showed higher average daily weight gain from d22 to d42 and d1 to d42 of age. Higher mortality rate of (12.5%) and lower of (5.5%) were recorded in AGP and NC fed‐groups respectively, lesion score was higher in BS and BL than in AGP, while no lesion was observed in NC group, results revealed higher duodenum and jejunum villus height to crypt depth (VH:CD) compared with NC and BS. Probiotics‐fed groups showed higher total (SCFAs), acetic and butyric acid concentrations at d21 post‐challenge (PC) than other groups. The expression of claudin‐1 was upregulated in duodenum (d7) PC and in jejunum (d7) and (d21) PC in BL group, while at d21 PC, the expression of occludens was higher in jejunum and ileum by AGP and BL. The present study indicated both BS and BL have some similarity with AGP in preventing or partially preventing NE effect in broilers.  相似文献   
8.
为研究不同施肥配比对切花菊‘优香’营养吸收和品质的影响,筛选出其品质达到最优的施肥配比,以切花菊‘优香’为试材,设置了5种有机-无机施肥配比,分别为农户常规、企业常规、企业常规减量、氨基酸施肥1和氨基酸施肥2,测定比较植株营养和品质相关指标。结果表明:施用氨基酸肥料能够促进切花菊营养吸收及品质优化,其中氨基酸处理1效果显著。在营养吸收方面,促进采前植株干物质积累,达15.1g/株,前期促进植株对氮的吸收,后期促进对磷和钾的吸收,氮、磷和钾含量在采前达258.9、27.0和473.3mg/株;在品质方面,能提使花芽分化完成时间提早2~5d;提高采收时花枝株高、茎粗和花序直径,分别达到127.4cm、6.3 mm和22.6 mm,增加70cm长的切花鲜重至56.7g,达到优级出口标准;延长采后瓶插寿命2~5d,达17d,减缓花朵前期开放速度和叶片衰老程度。因此建议在适量施入基肥与追施无机复合肥的基础上,增施氨基酸肥料。  相似文献   
9.
An eight-week feeding trial has been conducted to determine the optimum ration for Indian major carp, Labeo rohita, fingerling (4.10 ± 0.30 cm, 0.55 ± 0.16 g) by feeding a purified diet (40% CP; 3.61 kcal g−1 GE) at six levels, 2, 4, 6, 8, 10, and 12% of body weight per day, at 0800 and 1600 h, in triplicate, to 20 fish per trough fitted with a water flow-through system. Highest weight gain, best feed conversion ratio (FCR), best specific growth rate (SGR%), and highest protein efficiency ratio (PER) were evident for rations of 6–8% body weight. Second-degree polynomial regression analysis for FCR, PER, protein, and energy retention data indicated the break-points occurred at 6.55, 6.75, 6.80, and 6.95% bw per day, respectively. Significant (P < 0.05) differences between body composition were observed for fish fed different rations. Maximum body protein content was recorded for 6% and 8% rations. A linear increase in body fat content was evident with increasing ration. Body moisture and ash content remained non-significantly (P > 0.05) low for higher rations, however. On the basis of these results it is recommended that feeding in the range 6.5–7.0% bw per day corresponding to 2.6–2.8 g protein and 23.49–25.31 kcal energy per 100 g of the diet per day is optimum for growth and efficient feed utilization of Labeo rohita. Results for 2–4% rations (0.8–1.6 g protein and 7.23–14.46 kcal energy) suggest these amounts approximate to the maintenance requirement of this fish.  相似文献   
10.
Dietary arginine requirement of fingerling Indian major carp, Cirrhinus mrigala (4.20 ± 0.05 cm; 0.60 ± 0.02 g) was determined by conducting a 8‐week feeding trial with casein–gelatine‐based diets (400 g kg?1 crude protein; 17.90 kJ g?1, gross energy), containing crystalline amino acids with graded levels of l ‐arginine (10, 12.5, 15, 17.5, 20 and 22.5 g kg?1, dry diet). Fish were randomly stocked, in triplicate groups, in 55‐L indoor polyvinyl flow through circular tanks and fed experimental diets at 5% of their body weight divided into two feedings at 08.00 and 16.00 hours. Live weight gain (321%) and feed conversion ratio (FCR 1.40) were significantly (P < 0.05) higher in fish fed diet containing 17.5 g kg?1dietary arginine compared with other diets. Second‐degree polynomial regression analysis of live weight gain, FCR and protein efficiency ratio data indicated requirements for dietary arginine at 18.7, 18.4 and 18.3 g kg?1 of the dry diet, respectively. Maximum carcass protein, and minimum moisture and fat contents were noticed at the requirement level. Carcass ash content remained insignificantly different among the treatments except at 17.5 g kg?1 dietary arginine showing significantly higher ash content. Based on the above results, it is recommended that the diet for fingerling C. mrigala should contain arginine at 18.4 g kg?1, dry diet, corresponding to 46 g kg?1 dietary protein for optimum growth and efficient feed utilization.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号