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991.
在孟加拉Khulna大学森林和木材技术学科苗圃,调查了预处理的苦楝种子的萌发情况。成熟的苦楝种子采自国家植物园内的健康植株,对种子进行了5 种处理(对照,冷水浸泡,热水浸泡,砂纸破皮和浓硫酸浸泡)。结果表明,除了冷水浸泡外,其它播种预处理的种子萌发率显著高于对照种子。砂纸破皮处理的种子萌发率最高(80%),浓硫酸浸泡和热水浸泡的种子萌发率分别是74%和69%。苦楝种子在第8~11天开始萌发,萌发周期是20~21天。方差分析表明,预处理显著影响种子萌发率,但对萌发周期没有显著影响。推荐用热水浸泡处理种植在孟加拉农村的苦楝种子促进萌发。图2表2参30。 相似文献
992.
Muhammad Qasim SHAHID 《水稻科学》2010,17(4):296-302
Autotetraploid indica/japonica rice hybrid combines both the advantages of polyploidy and the heterosis between indica and japonica rice.Embryo sac abortion is an important factor influencing spikelet fertility in autotetraploid rice hybrid.To clarify the cytological mechanism of embryo sac abortion,the megasporogenesis and megagametogenesis in an autotetraploid japonica/indica hybrid were examined by the whole-mount eosin B-staining confocal laser scanning microscopy(WE-CLSM)technique.Abnormalities were ob... 相似文献
993.
Muhammad Anees Arne Tronsmo Véronique Edel-Hermann Nadine Gautheron Vincent Faloya Christian Steinberg 《European journal of plant pathology / European Foundation for Plant Pathology》2010,126(1):29-41
The relationships between biotic changes and local decrease in soil conduciveness in disease patches towards the disease incited
by Rhizoctonia solani AG 2-2 in a sugar beet field in France were investigated. Soil samples from healthy and diseased areas were analysed for
bacterial and fungal densities, molecular and physiological microbial community structures, and antagonistic abilities of
Trichoderma isolates collected from diseased and healthy areas. Although the inoculum density was higher inside the disease patches,
the respective soil was less conducive towards disease incited by R. solani AG 2-2. It was concluded that the pathogen was present in healthy areas but did not incite disease in field conditions. Conversely,
the response of the microflora to previous development of R. solani in diseased areas prevented further pathogenic activity. Indeed, genetic and physiological structures of the fungal communities
and physiological structures of the bacterial communities were modified in disease patches compared to healthy areas. The
terminal restriction fragment length polymorphism (T-RFLP) analysis revealed that the peaks corresponding to R. solani and Trichoderma spp. were higher inside the patches than in the healthy areas. Trichoderma isolates from the disease patches were more antagonistic than those from the healthy areas. These results suggest that disease
caused by R. solani AG 2-2 induced changes in genetic and physiological structure of microbial populations and development of antagonists. The
decreased conduciveness inside the patches may help explain patch mobility in the following season. 相似文献
994.
Interactive effect of shade and PEG-induced osmotic stress on physiological responses of soybean seedlings
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Muhammad Ahsan ASGHAR JIANG Heng-ke SHUI Zhao-wei CAO Xi-yu HUANG Xi-yu Shakeel IMRAN Bushra AHMAD ZHANG Hao YANG Yue-ning SHANG Jing YANG Hui YU Liang LIU Chun-yan YANG Wen-yu SUN Xin DU Jun-bo 《农业科学学报》2021,20(9):2382-2394
Intensively farmed crops used to experience numerous environmental stresses. Among these, shade and drought significantly influence the morpho-physiological and biochemical attributes of plants. However, the interactive effect of shade and drought on the growth and development of soybean under dense cropping systems has not been reported yet. This study investigated the interactive effect of PEG-induced osmotic stress and shade on soybean seedlings. The soybean cultivar viz., C-103 was subjected to PEG-induced osmotic stress from polyethylene glycol 6000(PEG-6000) under shading and non-shading conditions. PEG-induced osmotic stress significantly reduced the relative water contents, morphological parameters, carbohydrates and chlorophyll contents under both light environments. A significant increase was observed in osmoprotectants, reactive oxygen species and antioxidant enzymes in soybean seedlings. Henceforth, the findings revealed that, seedlings grown under non-shading conditions produced more malondialdehyde and hydrogen peroxide contents as compared to the shade-treated plants when subjected to PEG-induced osmotic stress. Likewise, the shaded plants accumulated more sugars and proline than non-shaded ones under drought stress. Moreover, it was found that nonshaded grown plants were more sensitive to PEG-induced osmotic stress than those exposed to shading conditions, which suggested that shade could boost the protective mechanisms against osmotic stress or at least would not exaggerate the adverse effects of PEG-induced osmotic stress in soybean seedlings. 相似文献
995.
人工模拟降雨条件下不同雨强、坡度对紫色土坡面产流的影响 总被引:5,自引:0,他引:5
[目的]研究不同降雨强度和坡度对紫色土坡面产流过程的影响,为紫色土区域的水土流失防治提供科学依据。[方法]基于室内人工模拟降雨试验开展研究。[结果]不同雨强和坡度下的产流过程可大致分为"下凹"型和"上凸"型,且分别可以用指数函数和对数函数描述。随着雨强和坡度的增大,产流时间逐渐减小,产流过程逐渐趋于一致,坡面径流量逐渐增加。坡度和雨强对径流总量的贡献率有着对比消长的关系,小雨强下(雨强为33和54mm/h),坡度是坡面径流总量的主要贡献因子,随着雨强增大(雨强为94和125mm/h),雨强为坡面径流总量的主要贡献因子。[结论]坡度和雨强均为坡面侵蚀的主要影响因子,随着坡度和雨强的增加,坡面侵蚀更加剧烈,主要侵蚀因子也由坡度转变为雨强。 相似文献
996.
997.
Ishtiaq Ahmed Muhammad Asgher Farooq Sher Syed Makhdoom Hussain Nadia Nazish Navneet Joshi Ashutosh Sharma Roberto Parra-Saldívar Muhammad Bilal Hafiz M. N. Iqbal 《Marine drugs》2022,20(3)
This review highlights the underexplored potential and promises of marine bioactive peptides (MBPs) with unique structural, physicochemical, and biological activities to fight against the current and future human pathologies. A particular focus is given to the marine environment as a significant source to obtain or extract high-value MBPs from touched/untouched sources. For instance, marine microorganisms, including microalgae, bacteria, fungi, and marine polysaccharides, are considered prolific sources of amino acids at large, and peptides/polypeptides in particular, with fundamental structural sequence and functional entities of a carboxyl group, amine, hydrogen, and a variety of R groups. Thus, MBPs with tunable features, both structural and functional entities, along with bioactive traits of clinical and therapeutic value, are of ultimate interest to reinforce biomedical settings in the 21st century. On the other front, as the largest biome globally, the marine biome is the so-called “epitome of untouched or underexploited natural resources” and a considerable source with significant potentialities. Therefore, considering their biological and biomedical importance, researchers around the globe are redirecting and/or regaining their interests in valorizing the marine biome-based MBPs. This review focuses on the widespread bioactivities of MBPs, FDA-approved MBPs in the market, sustainable development goals (SDGs), and legislation to valorize marine biome to underlying the impact role of bioactive elements with the related pathways. Finally, a detailed overview of current challenges, conclusions, and future perspectives is also given to satisfy the stimulating demands of the pharmaceutical sector of the modern world. 相似文献
998.
Chohan Sobia Perveen Rashida Anees Muhammad Azeem Muhammad Abid Muhammad 《植物病害和植物保护杂志》2019,126(6):553-563
Journal of Plant Diseases and Protection - Fifteen Pakistan’s indigenous medicinal plant extracts were investigated for various secondary metabolites and their potential against tomato early... 相似文献
999.
Helianthus argophyllus is a wild species known as “silver sunflower”, which possesses several traits, including morphological traits that increase drought tolerance. Therefore, introgressions between chosen cultivated lines and two H. argophyllus accessions were made, and segregating generations were established. Important agronomic traits including single heading, high pollen fertility, silver canopy (indicating more cuticular wax), and content of cuticular waxes and oil were selected over six segregating generations. The resulting F6 lines showed introgression of water saving traits, as they had lower excise leaf water loss, with comparable yield to standard checks. However, these F6 lines were late maturing and showed poor flowering synchronization between the cultivated and introgressed lines. Introgressed line “D‐22” was particularly promising as a breeding line, with superior agronomic and drought resistance traits. This line had the potential to be used as an inbred parental line for introgression of drought resistance traits into elite sunflower germplasm. Combining ability analysis of the introgressed lines further showed their potential for heterosis breeding or to be used as parental lines in breeding programme. 相似文献
1000.
Using remote sensing to evaluate the spatial variability of evapotranspiration and crop coefficient in the lower Rio Grande Valley,New Mexico 总被引:1,自引:0,他引:1
Zohrab Samani A. Salim Bawazir Max Bleiweiss Rhonda Skaggs John Longworth Vien D. Tran Aldo Pinon 《Irrigation Science》2009,28(1):93-100
Pecan is a major crop in the lower Rio Grande Valley (LRGV), New Mexico. Currently, about 11,000 ha of pecan orchards at various
stages of growth are consuming about 40% of irrigation water in the area. Pecan evapotranspiration (ET) varies with age, canopy
cover, soil type and method of water management. There is a need for better quantification of pecan ET for the purpose of
water rights adjudication, watershed management and agronomical practices. This paper describes a process where remote sensing
information from Landsat-5 and Landsat-7 were combined with ground level measurements to estimate pecan ET and field scale
actual crop coefficient (K
c) for the LRGV. The results showed that annual pecan water use for 279 fields ranged from 498 to 1,259 mm with an average
water use of 1,054 mm. For fields with NDVI > 0.6 (normalized difference vegetation index), which represented mature orchards
(total of 232 fields), the annual water use ranged from 771 to 1,259 mm with an average water use of 1,077 mm. The results
from remote sensing model compared reasonably well with ground level ET values determined by an eddy covariance system in
a mature pecan orchard with an average error of 4% and the standard error of estimate (SEE) ranging from 0.91 to 1.06 mm/day.
A small fraction (5%) of the pecan fields were within the range of maximum ET and K
c. 相似文献