排序方式: 共有89条查询结果,搜索用时 15 毫秒
71.
Dr Muhammad Farooq Shahzad M. A. Basra Muhammad B. Khan 《Archives of Agronomy and Soil Science》2013,59(3):315-326
Abstract An attempt to improve the performance of rice (Oryza sativa L.) nursery seedlings through seed priming and its effect on the yield after transplantation was made in a field trial. Priming tools employed during the investigation include pre-germination, hydropriming for 48 h, osmohardening with KCl and CaCl2 (ψs-1.25 MPa) for 24 h, vitamin priming with 10 ppm ascorbic acid for 48 h and seed hardening for 24 h. All the priming techniques resulted in improved germination speed and spread, seedling fresh and dry weight, root and shoot length, number of secondary roots, seedling nitrogen, total sugars and α-amylase activity. Osmohardening with CaCl2 resulted in the best performance as indicated by improved germination speed and spread, seedling vigour and starch metabolism, followed by hardening and osmohardening with KCl. However, improved starch metabolism in coarse rice was observed in osmohardening with KCl. Higher K and Ca contents were observed in seeds osmohardened with KCl and CaCl2, respectively. Maximum straw and kernel yield and harvest index were recorded from osmohardening with CaCl2 in fine and osmohardening with KCl in coarse rice. Increased number of secondary roots and α-amylase activity were accompanied with increased seedling nitrogen and reducing sugars, respectively. 相似文献
72.
Muhammad Shahzad Zulfiqar A. Saqib Farhan Hafeez Muhammad Bilal Sabaz A. Khan Saeed A. Asad 《Journal of plant nutrition》2016,39(9):1257-1265
The sensitivity of crop genotypes determines the level of growth reduction by salinity. Effect of salinity levels (7.5 and 15 dihydrate m?1) using completely randomized design (CRD) with four replications per treatment were compared on germination, chlorophyll content, water potential, ionic sodium and potassium (Na+, K+) balance, and other growth-related parameters of six wheat genotypes for varietal differences under long-term salinity stress. Chlorophyll contents at flowering stage and yield aspects at maturity of all the wheat genotypes decreased with increasing salinity. The maximum Na+ concentration was observed at 7.5 and 15 dS m?1 in Bhakhar and Saher-2000, respectively, while minimum Na+ concentration was observed for 9476. However, the maximum K+ concentration and water potential was noticed in 9476 at 7.5 dS m?1. Careful selection of salt-tolerant genotypes for field crops is an important perspective especially in the developing countries facing salinity problem. Our results revealed that the wheat genotype 9476 performed best regarding growth and physiological parameters compared to other wheat genotypes. 相似文献
73.
Effects of uniconazole with or without micronutrient on the lignin biosynthesis,lodging resistance,and winter wheat production in semiarid regions 下载免费PDF全文
Irshad AHMAD MENG Xiang-ping Muhammad KAMRAN Shahzad ALI Shakeel AHMAD LIU Tie-ning CAI Tie HAN Qing-fang 《农业科学学报》2020,19(1):62-77
Lodging stress results in grain yield and quality reduction in wheat. Uniconazole, a potential plant growth regulator significantly enhances lignin biosynthesis and thus provides mechanical strength to plants in order to cope with lodging stress. A field study was conducted during the 2015–2016 and 2016–2017 growing seasons, to investigate the effects of uniconazole sole application or with micronutrient on the lignin biosynthesis, lodging resistance, and production of winter wheat. In the first experiment, uniconazole at concentrations of 0(CK), 15(US1), 30(US2), and 45(US3) mg L~(-1)was applied as sole seed soaking, while in the second experiment with manganese(Mn) at concentration of 0.06 g L~(-1)Mn, 0.06 g L~(-1)Mn+ 15 mg L~(-1)uniconazole(UMS1), 0.06 g L~(-1)Mn+30 mg L~(-1)uniconazole(UMS2), and 0.06 g L~(-1)Mn+45 mg L~(-1)uniconazole(UMS3), respectively. Uniconazole sole application or with micronutrient significantly increased the lignin content by improving the lignin-related enzyme activities of phenylalanine ammonia-lyase, cinnamyl alcohol dehydrogenase, tyrosine ammonialyase, and peroxidase, ameliorating basal internode characteristics, and breaking strength. The spike length, spike diameter, spikes/plant, weight/spike, yield/spike, and grain yield increased and then decreased with uniconazole application at a higher concentration, where their maximum values were recorded with UMS2 and US2 treatments. The lignin accumulation was positively correlated with lignin-related enzyme activities and breaking strength while, negatively correlated with lodging rate. Uniconazole significantly improved the lignin biosynthesis, lodging resistance, and grain yield of winter wheat and the treatments which showed the greatest effects were uniconazole seed soaking with micronutrient at a concentration of 30 mg L~(-1)and 0.06 g L~(-1), and uniconazole sole seed soaking at a concentration of 30 mg L~(-1). 相似文献
74.
Sundas Shahzad Sajid Shokat Naeem Fiaz Amir Hameed 《Journal of Crop Science and Biotechnology》2017,20(1):1-7
Sugar recovery of Pakistani sugarcane varieties is relatively low as compared to the rest of the world while very little work is done on this aspect. The current study was conducted to tackle this issue and to assess the effect of quality and yielding traits on final sugar recovery. Sixty genotypes of sugarcane were sown during 2013 and data was collected at different growth stages during maturity and post maturity. Correlation studies indicated that polarity (0.77**) and purity (0.73**) were positively and significantly correlated with sugar recovery while brix% (-0.21**), fiber contents (-0.21**) and number of leaves per plant (-0.33**) were significant and negatively correlated with sugar recovery. Furthermore, leaf area was positively and significantly correlated with internode length (0.63**). Path coefficient analysis indicated that highest direct effect on sugar recovery was shown by purity (2.92), followed by brix% (2.48), and leaf area (0.66) which confirms that these traits could contribute more towards an increase of sugar recovery. Overall values of higher direct and indirect effects were observed by purity. The results of the current studies indicate that sugar recovery can be improved by focusing on purity, brix%, and leaf area. 相似文献
75.
Cross‐resistance,the stability of acetamiprid resistance and its effect on the biological parameters of cotton mealybug,Phenacoccus solenopsis (Homoptera: Pseudococcidae), in Pakistan 下载免费PDF全文
76.
Bushra Saddiq Naeem Abbas Sarfraz Ali Shad Muhammad Aslam Muhammad Babar Shahzad Afzal 《Phytoparasitica》2016,44(1):83-90
The cotton mealybug, Phenacoccus solenopsis Tinsley (Homoptera: Pseudococcidae) is a devastating pest that cause rigorous damage to the number of crops through feeding, managed by using various insecticides. To assess the risk of resistance and design a strategy for resistance management, a field collected population of P. solenopsis was selected with deltamethrin in the laboratory for six generations to investigate the cost to its fitness and to examine cross resistance to different insecticides. Bioassay results at G8 showed that the deltamethrin selected population (Delta-SEL) developed a resistance ratio of 100-fold compared to that of the unselected population (UNSEL). The deltamethrin resistance population exhibited strong cross-resistance to acetamiprid and lambda-cyhalothrin, but no cross-resistance to profenofos when compared to that of the UNSEL. The relative fitness of the Delta-SEL population was 0.37, with considerably lower survival rates from crawler to second instar, fecundity, hatchability, number of next generation nymphs, net reproductive rate and biotic potential compared with that of the UNSEL. The cost of fitness associated with deltamethrin resistance was evident in the Delta-SEL population. The present study provided useful information for management strategies to overcome development of resistance. 相似文献
77.
Santalum album L.is a commercially important tree that yields essential oil of high medicinal value.Regeneration research through organogenesis and embryogenesis has been documented but no report depicts comparative ontogeny of directly differentiating shoot buds(SB)and somatic embryos(SE).In the present study aseptic seedling derived hypocotyl segments(HC)and hypocotyl+root junction(HC+R)were used to induce SBs and SEs,respectively.Ontogenic differences between the structures were confirmed using scanning electron microscopy and histological analysis.MS medium containing 6-benzyladenine or BA(2.5μM)produced highest number of direct SB,while MS+BA(7.5μM)proved suitable for higher frequency of SE differentiation.The differentiating structures attained growth when transferred to MS medium containing a combination of BA and anaphthalene acetic acid or silver nitrate(AgNO3).A combination of indole-3-butyric acid and silver nitrate(AgNO3)in half-strength woody plant medium and lesser osmotic concentration(2%sucrose),induced rhizogenesis. 相似文献
78.
Roghaiyeh Karimzadeh Mir Jalil Hejazi Hossein Helali Shahzad Iranipour Seyed Abolghasem Mohammadi 《Precision Agriculture》2011,12(4):576-593
Sunn pest, Eurygaster integriceps Puton is a key pest of wheat and barley in Iran. In this study, the impact of site-specific spraying on control of sunn pest
damage and densities of the natural enemies was compared with the whole-field spraying method in 2009 and 2010. Three plots
were assigned to each spraying method and two others were left untreated as control. The plots were divided into 11 × 11 m
grids. Adults of E. integriceps were sampled using the distance-walk method. Coccinellids, Chrysoperla carnea and nymphs of sunn pest were sampled using a sweep net. Spatial analysis of datasets was done using Geostatistical Analyst
extension of ArcGIS 9.3. The spatial analysis indicated that the adults and nymphs of E. integriceps had aggregated distribution in space and that site-specific spraying was applicable. Whole-field spraying was carried out
when the mean density of E. integriceps in plots exceeded the economic threshold. In the site-specific spraying method, decamethrin ([cyano-[3-(phenoxy) phenyl]
methyl] 3-(2,2-dibromoethenyl)-2,2-dimethylcyclopropane-1-carboxylate) was applied to the grid cells with densities above
the economic threshold. Site-specific application reduced the insecticide input by ca. 40–50%. The numbers of C. carnea and coccinellids were higher in site-specifically sprayed plots compared with whole-sprayed plots after treatment. The mean
numbers of nymphs were not significantly different (P < 0.01) in whole-field and site-specifically sprayed plots. Percent damaged grain was below the economic damage threshold
in all treated plots. It can be concluded that site-specific spraying has the potential to control E. integriceps at an acceptable level along with reducing the amount of insecticide used. It also conserved natural enemies in untreated
refuges. 相似文献
79.
Muhammad Farooq Shahzad M. A. Basra N. Ahmad G. Murtaza 《Paddy and Water Environment》2009,7(1):55-63
Raising the rice seedlings in the nursery and its transplantation into the flooded fields is principal method of rice cultivation
in the world. Traditional nursery raising method in Pakistan is tedious and produces week seedlings, which reduces the final
yield due to high mortality. The potential of seed priming to improve the nursery seedlings and thus the transplanted rice
was evaluated in the present study. Seed priming tools employed during the investigation included traditional soaking (pre-germination),
hydropriming for 48 h, osmohardening (KCl or CaCl2) (ψs-1.25 MPa) for 24 h (1 cycle), ascorbate priming (with 10 ppm ascorbate) for 48 h or seed hardening for 24 h. Priming
improved nursery seedling vigor and resulted in improved growth, yield and quality of transplanted rice. Osmohardening (KCl)
consequently resulted in the best performance, followed by osmohardening (CaCl2), hardening and ascorbate priming. Osmohardening (KCl) produced 4.28 t ha−1 (vs. 3.51 t ha−1 from untreated control) kernel yield, 10.27 t ha−1 (vs. 9.34 t ha−1 from untreated control) straw yield and 29.41% (vs. 27.31% from untreated control) harvest index. The improved yield was
attributed to increase in number of fertile tillers. 相似文献
80.
Muhammad Ashraf Sher Muhammad Shahzad Muhammad Imtiaz Muhammad Shahid Rizwan 《Journal of plant nutrition》2018,41(8):1065-1081
Nitrogen (N) metabolism is of great economic importance because it provides proteins and nucleic acids which in turn control many cellular activities in plants. Salinity affects different steps of N metabolism including N uptake, NO3? reduction, and NH4+ assimilation, leading to a severe decline in crop yield. Major mechanisms of salinity effects on N metabolism are salinity-induced reductions in water availability and absorption, disruption of root membrane integrity, an inhibition of NO3? uptake by Cl?, low NO3? loading into root xylem, alteration in the activities of N assimilating enzymes, decrease in transpiration, and reduction in relative growth rate which results in a lower N demand. However, the effects of salinity on N metabolism are multifaceted and may vary depending on many plant and soil factors. The present review deals with salinity effects on N metabolism in plants, emphasizing on the activities of N metabolizing enzymes in a saline environment. 相似文献