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In an effort to characterise and select promising sweet stem sorghum genotypes with enhanced biofuel productivity, the present study investigated phenotypic variability present among diverse sweet stem sorghum genotypes based on ethanol production and related agronomic traits. One hundred and ninety genotypes were evaluated. Data were subjected to variance, cluster, correlation, path coefficient and principal component analyses. Significant differences (P?<?0.01) were detected among tested genotypes for all measured traits. Days to flowering varied from 62 to 152 with a mean of 93. Plant height varied from 90 to 420?cm with a mean of 236?cm. Stem diameter ranged from 7 to 31?mm with a mean of 16?mm. Biomass yield varied from 6.668 to 111.2?t?ha?1 with a mean of 30?t?ha?1. Stalk dry matter content ranged from 17.2% to 44.2% with a mean of 29.8%, while fibre content varied from 8.92% to 34.8% with a mean of 17.2%. The stalk brix yield varied from 3.3% to 18.9% with a mean of 12.1%. Ethanol productivity ranged from 240.9 to 5500?l?ha?1 with a mean of 1886?l?ha?1. The best ethanol producing genotypes were AS203, AS391, AS205, AS251 and AS448. Days to flowering, plant height, stalk brix and stem diameter exerted the greatest indirect effects on ethanol production through higher biomass production. Biomass yield had the greatest direct effect on ethanol production. Therefore, the above traits should be considered during breeding sorghum for bio-ethanol production. Also, the traits had high heritability values, hence selection should provide for good genetic gains. Overall, the above sweet stem sorghum genotypes are useful genetic resources for breeding of sorghum with enhanced bio-ethanol production.  相似文献   
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Use of Human Excreta as Manure in Rural China   总被引:1,自引:0,他引:1       下载免费PDF全文
Empirical research has shown that the use of manure significantly improves crop yield, soil fertility and water and moisture conservation. Despite these documented benefits, however, there is a concern on the downward trend of manure use in agriculture in China. This paper examines factors contributing to this downward trend, with a particular focus on human excreta used in agriculture. Empirical analysis based on data from stratified random sampling of rural households in five provinces of China shows that about 85% of human excreta was still used as manure in agriculture in 2007 which was less than a decade ago when nearly all human excreta was used as manure. Econometric results suggest that income growth, rising population density and improvement in rural transportation significantly contribute to declining use of human excreta as manure in agriculture. These results imply that the current downward trend will continue given China's rising economic growth, urbanization and rural infrastructural improvement.  相似文献   
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斑鳜(Siniperca scherzeri)是近年来新开发的名贵淡水养殖鱼类之一,但规模化繁育技术尚未完全解决。为进一步了解斑鳜卵巢成熟发育的规律,利用组织切片技术观察了3月中旬-5月中旬长江斑鳜卵巢的成熟发育过程,并用生化法测定了血清蛋白磷(SPP)的含量,结果表明:这一时期,斑鳜卵母细胞正经历由Ⅲ时相(3月中旬-4月上旬)向Ⅳ时相(4月中旬-4月下旬)、Ⅴ时相(5月中旬)的渐近生长,并发现卵母细胞生长不同步的现象;与此同时,血清蛋白磷含量由0.12 mg/mL逐步上升至0.62 mg/mL。斑鳜血清蛋白磷含量的变化趋势与卵巢的成熟发育过程基本一致,并有着密切的生理相关,血清蛋白磷含量可以作为卵巢发育阶段和成熟程度判定的重要生化指标。  相似文献   
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This study compared five commercially available probiotics vis-à-vis antibiotic growth promotant (AGP) supplementation and absence of feed additive based on efficiency, intestinal morphometry, and energy digestibility in improving broiler chicken production. A total of 630 straight run (Cobb) day-old broiler chicks were distributed to seven treatments following a completely randomized design, with ten replicates per treatment and nine birds per replicate per cage. Dietary treatments consisted of basal diet in combination with the following: without probiotics and AGP supplementation (treatment 1); 75 ppm each of chlorotetracycline (CTC) and Zn bacitracin (treatment 2); probiotic A, Bacillus subtilis (treatment 3); probiotic B, Bacillus subtilis (treatment 4); probiotic C, Enterococcus faecium (treatment 5); and probiotic D, Bacillus subtilis (treatment 6); probiotic E, Enterococcus faecium, Bifidobacterium spp., Pediococcus spp., and Lactobacillus spp. (treatment 7). At day 42, energy digestibility was determined by fasting three randomly selected birds from each treatment for 12 h and then subjecting them to their corresponding dietary treatments. Excreta were collected and pooled after 24 h of feeding. Pooled excreta were weighed, oven-dried, and subjected to energy analyses after 3-day collection. Apparent total tract metabolizable energy was then computed. At day 47, three birds were randomly selected per treatment for intestinal morphometry (villi height and crypt depth) of the duodenum, jejunum, and ileum. Dietary supplementation using probiotics showed no significant effect on overall body weight, weight gain, feed consumption, feed efficiency, dressing percentage, mortality, harvest recovery, carcass quality parameters (e.g., meat to bone ratio and abdominal fat content), intestinal morphometry, and energy digestibility. Birds under treatment 7 (basal feed + probiotic E) generated the highest income over feed and chick cost.

  相似文献   
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An effective male sterility system enables targeted crosses between parent plants with desired and complementary characteristics. The use of chemical hybridising agents (CHAs) to induce male sterility is quicker and more efficient than manual emasculation. This study investigated the concentration, stage of application and frequency of application of ethyl 4'fluorooxanilate (E4FO) for inducing male sterility of sweet stem sorghum without affecting female fertility. In Trial 1, the dose rate of E4FO was determined to optimise male sterility. In this experiment three genotypes were tested at E4FO dose rates. In Trial 2 the frequency of application of E4FO was determined using three sweet stem sorghum genotypes, three E4FO doses, and six frequencies of application. Data on sterility was inferred based on seed set and seed count from the treated plants. Male sterility was achieved when E4FO was applied during heading stage using the following rates: 1?g l?1, 1.5?g l?1 and 2?g l?1, with more than one application. Applying E4FO twice during the heading stage at a rate of 2?g l?1 would induce male sterility in the tested sweet stem sorghum genotypes, a result that could be useful in hybrid breeding programmes.  相似文献   
6.
河南省珍稀、濒危保护植物的调查研究   总被引:5,自引:0,他引:5  
论述了河南省现存的33种国家重点保护的珍稀、濒危植物的地理分布、生长环境及其科学价值。在野外调查观测的基础上,分柝和总结了珍稀、濒危植物种群分布的生态特点及其濒危产生的原因。初步确定列入省内急需保护的珍稀、濒危植物42种,并根据我省的实际情况,提出了保护、发展和合理利用珍稀、濒危植物资源的建议和措施。  相似文献   
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