全文获取类型
收费全文 | 259篇 |
免费 | 15篇 |
专业分类
林业 | 16篇 |
农学 | 52篇 |
基础科学 | 1篇 |
59篇 | |
综合类 | 11篇 |
农作物 | 39篇 |
水产渔业 | 6篇 |
畜牧兽医 | 48篇 |
园艺 | 3篇 |
植物保护 | 39篇 |
出版年
2023年 | 3篇 |
2022年 | 9篇 |
2021年 | 15篇 |
2020年 | 12篇 |
2019年 | 3篇 |
2018年 | 17篇 |
2017年 | 24篇 |
2016年 | 14篇 |
2015年 | 12篇 |
2014年 | 6篇 |
2013年 | 22篇 |
2012年 | 11篇 |
2011年 | 19篇 |
2010年 | 7篇 |
2009年 | 4篇 |
2008年 | 18篇 |
2007年 | 10篇 |
2006年 | 8篇 |
2005年 | 9篇 |
2004年 | 3篇 |
2003年 | 4篇 |
2002年 | 8篇 |
2001年 | 2篇 |
2000年 | 3篇 |
1999年 | 3篇 |
1998年 | 1篇 |
1997年 | 1篇 |
1996年 | 3篇 |
1993年 | 2篇 |
1992年 | 2篇 |
1991年 | 2篇 |
1990年 | 2篇 |
1989年 | 2篇 |
1988年 | 1篇 |
1986年 | 1篇 |
1984年 | 2篇 |
1983年 | 1篇 |
1981年 | 1篇 |
1980年 | 3篇 |
1979年 | 1篇 |
1977年 | 1篇 |
1976年 | 1篇 |
1967年 | 1篇 |
排序方式: 共有274条查询结果,搜索用时 0 毫秒
271.
The present studies were undertaken with a view to standardize the medium and culture conditions for embryo culture of five cultivars of walnut viz., ACO 38853, Netar Akhrot, Gobind, Solding Selection and Blackmore. Embryos from mature fruits were aseptically excised and cultured on MS medium supplemented with different combinations of BAP, kinetin and GA3. Best performing medium was MS with 0.5 mg l−1 kinetin, 0.5 mg l−1 BAP and 2 mg l−1 GA3 yielding 66.6% germination in Netar Akhrot after 12 days of culturing. Percent germination of excised embryos was higher when GA3 and cold treatments were simultaneously applied as compared to those when applied separately. Netar Akhrot was found to be the best responding cultivar, which had a range of 25–66.6% embryo germination under different culture conditions. Plantlets with shoots and roots have been obtained in Netar Akhrot and ACO38853 and are transferred to soil after hardening. 相似文献
272.
273.
Competition with weeds is a major constraint to production of field pea in Australia, exacerbated by limited herbicide control options. Metribuzin is considered to be a safe herbicide, but may be phytotoxic to both weeds and target crop. A preliminary glasshouse-based assay was used to identify the optimal concentration required for discrimination between tolerant and sensitive field pea genotypes as 10 ppm metribuzin. This dosage was subsequently used to screen the Kaspa × PBA Oura recombinant inbred line genetic mapping population of 185 individuals for tolerance to metribuzin in three individual controlled environment assays. After two weeks of metribuzin treatment, plants were assessed on the basis of both a numerical score for symptoms such as chlorosis and necrosis, and plant damage as a percentage of necrosis. The two phenotypic parameters showed a high level of correlation (r = 0.85–0.97). The locations and magnitudes of effect of quantitative trait loci (QTLs) were determined for metribuzin tolerance (based on both symptom score and plant damage) as well as several related morphological traits. Analysis of all characters detected a single genomic region located on linkage group (LG) Ps IV (LOD scores 3.5–5.7), accounting for proportions of phenotypic variance for plant symptom score and percentage of plant necrosis varying from 12 to 21%. Genetic markers based on genic sequences that closely flank the metribuzin tolerance QTL are suitable for implementation in field pea breeding programs. In addition, comparative genomics between field pea and Medicago truncatula identified a cytochrome P450 monooxygenase gene in the vicinity of the QTL, potentially involved in non-target-site metabolism-based herbicide tolerance. 相似文献
274.
Bukar MM Yusoff R Haron AW Dhaliwal GK Goriman Khan MA Omar MA 《Tropical animal health and production》2012,44(7):1505-1511
The effects of different estrus synchronization techniques on follicular development and estrus response were studied in 81 nulliparous Boer does. The does were divided into nine groups. Eight of the nine groups were synchronized with prostaglandin F2-alpha (PGF(2α)) or flugestone acetate (FGA) or their combinations, and the ninth group was a control group. In addition to the above combinations, four of the eight synchronized groups were given 5?mg follicle-stimulating hormone (FSH) and the remaining four groups were administered 300?IU equine chorionic gonadotrophin (eCG). Posttreatment follicular development was monitored until ovulation occurred using a real-time B-mode ultrasound scanner (Aloka, 500 SSD, Japan), with a 7.5-MHz transrectal linear probe. All the does from the synchronized groups that were given eCG exhibited oestrus while only 88.9% of the does synchronized with FSH showed estrus. The estrus response was observed to be the least among the does synchronized with PGF(2α) + FSH (33.3%) combination followed closely by the FGA + FSH (42.9%) combinations. It was observed that the combinations of FGA + PGF(2α) + FSH resulted in increased percentage of estrus response, duration of estrus, and ovulation. The number of follicles was higher (P?0.05) in FSH-synchronized groups than the eCG-synchronized groups. It was concluded that the best estrus synchronization protocol in goats is the FGA + eCG with or without PGF(2α). However, the PGF(2α) + FGA + FSH method of estrus synchronization is the most promising combination for further development as a better alternative to estrus synchronization with eCG in does. 相似文献