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11.
Intazar Ali Zhang Shuai Asif Sajjad Hafiz Mahmood ur Rehman Cui Jin-Jie 《Phytoparasitica》2018,46(1):127-135
The green lacewing Chrysopa pallens (Rambur) (Neuroptera: Chrysopidae) is a common and abundant predator in many cropping systems in palearctic realm and it’s conservation is helpful in sustainable pest management in agro-ecosystem. Prior to commercialization of Bt crops in any agro- ecosystem, it is necessary to evaluate the impact of Cry proteins upon non-target organisms especially biological control agents (BCA). In present study an artificial diet consisting of shrimp, beef, beef liver and egg yolk was developed to mass-rear C. pallens for its use as biological control agents in sustainable pest management. Moreover, an artificial diet based risk assessment protocol was developed to investigate the impact of Cry1Ac, Cry1Fa and Cry2Ab on the survival and reproductive performance of C. pallens adults. C. pallens was fed on diets incorporated with Cry proteins and without addition of Cry proteins (control). The same diet containing boric acid was served as a positive control. Temporal stability, bioactivity and intake of Cry proteins by C. pallens were confirmed using double-antibody sandwich, enzyme-linked immunosorbent assay and bioactivity verification bioassays. Survival and reproductive performance of C. pallens, e.g., pre-oviposition period, daily fecundity, total fecundity and 30-day old adults dry weights, exhibited non-significant differences (p?>?0.05) for the diets containing Cry1Ac, Cry1Fa and Cry2Ab (50 μg/g) against Control. However, significant reduction in survival and reproductive performance (p?<?0.05) was observed in positive control. Our findings reveal that artificial diet is a good source of nutritional requirement with enhanced survival and reproductive performance of C. pallens and can be used for mass rearing of predator in case of natural diet scarcity and Cry proteins are safe for adult C. pallens and Bt crops cultivation help in predators conservation in sustainable agriculture. 相似文献
12.
Sami Ullah Jehan Zada Sajjad Ali 《Communications in Soil Science and Plant Analysis》2016,47(12):1542-1558
The present study aimed to determine the effect of nephthyl acetic acid (NAA) on the physiological mechanism of drought tolerance in selected maize (Zea mays L.) varieties under induced drought stress at the vegetative stage. Maize seeds were sown in plastic pots (14 cm lower inside diameter, 18.5 cm upper inner diameter, 15.6 cm height, and 0.5 cm thickness) filled with 3 kg of air-dried soil and sand (3:1) in triplicate in the greenhouse of the Botany Department, Bacha Khan University, Charsadda in 2014. Results showed that the activities of antioxidant enzymes and proline accumulation were associated with the dry mass production and consequently with the drought tolerance of the maize varieties. It has been concluded that the inhibitory effects of water stress were ameliorated by exogenous application of NAA and were found to be significant for antioxidant enzymes at the vegetative stage in both varieties. 相似文献
13.
Ling-Yun Chang Sajjad Toghiani Ashley Ling El H. Hay Sammy E. Aggrey Romdhane Rekaya 《Journal of Agricultural, Biological & Environmental Statistics》2017,22(4):640-651
Several discrete responses, such as health status, reproduction performance and meat quality, are routinely collected for several livestock species. These traits are often of binary or discrete nature. Genetic evaluation for these traits is frequently conducted using a single-trait threshold model, or they are considered continuous responses either in univariate or in multivariate context. Implementation of threshold models in the presence of several binary responses or a mixture of binary and continuous responses is far from simple. The complexity of such implementation is primarily due to the incomplete randomness of the residual (co)variance matrix. In the current study, a multiple binary trait simulation was carried out in order to implement and validate a new procedure for dealing with the consequences of the restrictions imposed to the residual variance using threshold models. Using three and eight binary responses, the proposed method was able to estimate all unknown parameters without any noticeable bias. In fact, for simulated residual correlations ranging from ?0.8 to 0.8, the resulting HPD 95% intervals included the true values in all cases. The proposed procedure involved limited additional computational cost and is straightforward to implement independent of the number of binary responses involved in the analysis. Monitoring of the convergence of the procedure must be conducted at the identifiable scale, and special care must be placed on the selection of the prior of the non-identifiable model. The latter could have serious consequences on the final results due to potential truncation of the parameter space. 相似文献
14.
氮肥及硝化抑制剂配合施用对石灰性土壤二氧化碳释放的影响 总被引:6,自引:2,他引:4
为研究施用氮肥对同时含有有机碳及无机碳石灰性土壤碳释放的影响,在陕西杨凌进行田间试验,比较了不同施氮量(0、160、220 kg·hm~(-2))及其与硝化抑制剂(DCD)配合(N160、N220及N160+DCD、N220+DCD)对土壤pH值、矿质态氮含量和二氧化碳(CO_2)释放量的影响。结果表明:施用氮肥显著降低了耕层土壤pH;配施DCD后土壤pH降低幅度小于未加DCD处理;加入DCD使氮肥的硝化过程推迟了约20 d;未加DCD处理的土壤CO_2释放量随施氮量增加而增加,试验结束时(施肥37 d后)土壤CO_2累积释放量最高达到167.1 g·m~(-2)。与N0处理相比,N160和N220处理的土壤CO_2累积释放量显著增加,增幅分别为20.9%和25.7%;N160+DCD和N220+DCD处理显著降低了土壤CO_2累积释放量,比对应相同施氮量处理分别降低了13.5%和11.0%。上述结果说明施用氮肥会同时影响石灰性土壤有机碳及无机碳的释放,施用氮肥引起的土壤无机碳的释放值得关注。 相似文献
15.
16.
The total concentration and size distribution of bioaerosols in three different types of housing (single room in shared accommodation [type I], single bedroom flat in three-storey building [type II] and two- or three-bedroom detached houses [type III]) was assessed during the winter. This research was an extension of a previous study carried out in the summer. The measurement campaign was undertaken in winter 2008 and 30 houses were sampled. Samples were taken from kitchens, living rooms, corridors (only in housing type I) and outdoors with an Anderson 6 stage viable impactor. In housing type I, the total geometric mean concentration was highest in the corridor for both bacteria and fungi (3,171 and 1,281?CFU/m3, respectively). In type II residences, both culturable bacteria and fungi were greatest in the living rooms (3,487 and 833?CFU/m3, respectively). The living rooms in type III residences had largest number of culturable bacteria (1,361?CFU/m3) while fungi were highest in kitchens (280?CFU/m3). The concentrations of culturable bacteria and fungi were greater in mouldy houses than non-mouldy houses. A considerable variation was seen in the size distribution of culturable bacteria in type I residences compared to types II and III. For all housing types more than half of culturable bacterial and fungal aerosol were respirable (<4.7???m) and so have the potential to penetrate into lower respiratory system. Considerable variation in concentration and size distribution within different housing types in the same geographical region highlights the impact of differences in design, construction, use and management of residential built environment on bioaerosols levels and consequent varied risk of population exposure to airborne biological agents. 相似文献
17.
Khan Sultan Habibullah Sajjad Muhammad Gulnaz Saima Waqar Sundas Shahzad Munawar Arain Saima Mir 《Journal of Crop Science and Biotechnology》2022,25(2):215-223
Journal of Crop Science and Biotechnology - Understanding genetic architecture of a crop germplasm is necessary for designing a successful breeding program. Herein, we evaluated a large collection... 相似文献
18.
Hafiz Muhammad Masroor Muhammad Akbar Anjum Sajjad Hussain Shaghef Ejaz Shakeel Ahmad Sezai Ercisli M. Zia-Ul-Haq 《Erwerbs-Obstbau》2016,58(1):49-55
Zinc (Zn) deficiency is frequently observed in mangoes grown in calcareous soils. Inherent inability of mango to extract sufficient Zn from the soil exacerbates this situation. Therefore, mitigating effects of Zn application was investigated on flowering, fruit setting, yield and quality of mango cv. Samar Bahisht Chaunsa growing in calcareous soils. The experiment consisted of five treatments: control—no Zn, soil application of 50 and 100 g ZnSO4 per tree and foliar application of 0.5? and 1.0?% ZnSO4 solution. Zn was applied twice in the 2nd week of November, 2011 and 3rd week of March, 2012, respectively. The experiment was repeated on the same dates during the next growing season. Zn application significantly increased number of flower panicle, fruits matured panicle, leaf Zn concentrations, fruit size, peel thickness, fruit weights at harvest and after ripening and fruit yield tree, whereas it reduced malformed panicles and early fruit drop. However, flower sex ratio and fruit set remained statistically unaffected. Similarly, fruit quality in terms of total soluble solids, flesh color, aroma, flavor and overall acceptability significantly improved as compared to control. Foliar application mitigated Zn deficiency more effectively than the soil application in calcareous soils. 相似文献
19.
20.
T. Mahmood R. Ali M. I. Sajjad M. B. Chaudhri G. R. Tahir F. Azam 《Biology and Fertility of Soils》2000,31(3-4):270-278
In a 2-year field study, denitrification loss was measured from an irrigated sandy-clay loam under cotton receiving urea-N
at 158–173 kg ha–1. An acetylene inhibition-soil core method was employed for the direct measurement of denitrification, considering also the
N2O entrapped in the soil. Taking into account the N2O evolved from soil cores and that entrapped in the soil, a total of 65.7 kg N ha–1 and 64.4 kg N ha–1 was lost due to denitrification during the 1995 and 1996 cotton-growing seasons, respectively. Most (>70%) of the denitrification
loss occurred during June–August, a period characterized by high soil temperatures and heavy monsoon rains. On average, 35%
of the denitrification-N2O was found entrapped in the soil and the amount of entrapped N2O was significantly correlated with head space N2O concentration and with water-filled pore space. 15N-balance during the 1996 growing season revealed a loss of 71.8 kg N ha–1. It was concluded that a substantial proportion of the fertilizer-N applied to irrigated cotton is lost under the semiarid
subtropical climatic conditions prevailing in the Central Punjab region of Pakistan and that denitrification is the major
N loss process under irrigated cotton in this region.
Received: 8 March 1999 相似文献