Modification of irrigation requirement of wheat through mulching and foliar application of transpiration suppressants     

Rajat De  D. V. S. Bhujanga Rao  Y. Yogeswara Rao  L. G. Giri Rao  M. Ikramullah 《Irrigation Science》1983,4(3):215-223

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Marker‐assisted introgression of rare allele of β‐carotene hydroxylase (crtRB1) gene into elite quality protein maize inbred for combining high lysine,tryptophan and provitamin A in maize     

Rajat Goswami  Rajkumar Uttamrao Zunjare  Suphiya Khan  Aanchal Baveja  Vignesh Muthusamy  Firoz Hossain 《Plant Breeding》2019,138(2):174-183

Vitamin A deficiency in humans is a widespread health problem. Quality protein maize (QPM) is a popular food rich in lysine and tryptophan, but poor in provitamin A (proA). Here, we report the improvement of an elite QPM inbred, HKI1128Q for proA using marker‐assisted introgression of crtRB1‐favourable allele. HKI1128 was one of the parental lines of three popular hybrids in India and was converted to QPM in our earlier programme. Severe segregation distortion for crtRB1 was observed in BC₁F₁, BC₂F₁ and BC₂F₂. Background selection by 100 SSRs revealed mean recovery of 91.07% recurrent parent genome varying from 88.78% to 93.88%. Across years, introgressed progenies possessed higher mean β‐carotene (BC: 9.22 µg/g), β‐cryptoxanthin (BCX: 3.05 µg/g) and provitamin A (proA: 10.75 µg/g) compared to HKI1128Q (BC: 2.26 µg/g, BCX: 2.26 µg/g and proA: 3.38 µg/g). High concentration of essential amino acids, viz. lysine (mean: 0.303%) and tryptophan (0.080%) in endosperm, was also retained. Multi‐year evaluation showed that introgressed progenies possessed similar grain yield (1,759–1,879 kg/ha) with HKI1128Q (1,778 kg/ha). Introgressed progenies with higher lysine, tryptophan and proA hold immense potential as donors and parents in developing biofortified hybrids.  相似文献   

Identification of a DNA nonhomologous end-joining complex in bacteria     

Weller GR  Kysela B  Roy R  Tonkin LM  Scanlan E  Della M  Devine SK  Day JP  Wilkinson A  d'Adda di Fagagna F  Devine KM  Bowater RP  Jeggo PA  Jackson SP  Doherty AJ 《Science (New York, N.Y.)》2002,297(5587):1686-1689

In eukaryotic cells, double-strand breaks (DSBs) in DNA are generally repaired by the pathway of homologous recombination or by DNA nonhomologous end joining (NHEJ). Both pathways have been highly conserved throughout eukaryotic evolution, but no equivalent NHEJ system has been identified in prokaryotes. The NHEJ pathway requires a DNA end-binding component called Ku. We have identified bacterial Ku homologs and show that these proteins retain the biochemical characteristics of the eukaryotic Ku heterodimer. Furthermore, we show that bacterial Ku specifically recruits DNA ligase to DNA ends and stimulates DNA ligation. Loss of these proteins leads to hypersensitivity to ionizing radiation in Bacillus subtilis. These data provide evidence that many bacteria possess a DNA DSB repair apparatus that shares many features with the NHEJ system of eukarya and suggest that this DNA repair pathway arose before the prokaryotic and eukaryotic lineages diverged.  相似文献   

Characterization of CO₂ Responsiveness in a Brassica oxycamp Interspecific Hybrid     

D. C. Uprety  Neeta Dwivedi  Rajat Mohan 《Journal of Agronomy and Crop Science》1998,180(1):7-13

A study of the characterization of CO₂ responsiveness in Brassica oxycamp and its parents Brassica oxyrrhina and Brassica campestris was done using open top chamber technology. The response of the X. B. oxycamp (hybrid) to elevated CO₂ was significantly positive in respect of photosynthesis and growth and similar to that of its parent B. campestris. X B. oxycamp and B. campestris with greater sink potential responded significantly, whereas B. oxyrrhina with a poor sink, did not respond to CO₂ enrichment. Photosynthetic changes at elevated CO₃ levels in the hybrid and parents are partially attributed to the CO₂ effects on stomatal conductance and chlorophyll fluorescence.  相似文献   

Biochemistry of TBT-Degrading Marine Pseudomonads Isolated from Indian Coastal Waters     

Ramya Sampath  Harish Venkatakrishnan  Vijaya Ravichandran  Rajat Roy Chaudhury 《Water, air, and soil pollution》2012,223(1):99-106

Tributyltin (TBT) is a very effective biocide and an active ingredient in antifouling paints. Screening along the Indian coast yielded 49 bacterial isolates capable of TBT assimilation. The screening was done based on the ability of bacteria to grow in mineral salt medium (MSM) containing TBT as the sole source of carbon. All the isolates produced exopolysaccharides (biosurfactants) in the medium which aid in emulsification and thus ease bioavailability of TBT. Five isolates were identified as potent TBT degraders (namely, Pseudomonas pseudoalcaligenes, Pseudomonas stutzeri, Pseudomonas mendocina, Pseudomonas putida, and Pseudomonas balearica) based on their biomass production in MSM containing TBT as the sole source of carbon. In addition to evaluating the potential of individual bacterial strains, the study also focused on using a consortium of bacteria to explore their synergistic effect when grown on TBT. Further tests like growth profile, rhamnolipid secretion profile, extracellular protein secretion profile, and detection of siderophores were performed on these isolates when grown in MSM supplemented with 2 mM TBT concentration. Emulsification activity of the crude extracellular polysaccharides against kerosene was evaluated. It can be therefore inferred that TBT degradation by these marine pseudomonads is a two-step process: (a) dispersion of TBT in the aqueous phase and (b) tin–carbon bond cleavage by siderophores affecting debutylation of TBT. The consortium of bacteria may be effective in the treatment of TBT-contaminated waste water in dry docks.  相似文献   

公司责任及其在林产工业中的体现     

Rajat Panwar  Tomi Rinne  Eric Hansen  Heikki Juslin  管宁 《国际木业》2007,37(1):33-34

工商活动以及社会对其认识经历过很多显著的变化。中世纪流动的商人取代本地的工匠,满足社会对商品的需求是一大变革。社会对这些早期商人常取负面态度,认为他们进行剥削。工业革命使这种情况加剧。工商活动越来越专注于创造财富和谋求利润而置社会问题于不顾。随着时间的推移,社会管理调控的加强,工商活动的影响及其与社会及环境的相互关系逐渐被认识。自身的进化和社会的关注,使工商活动逐渐重新定向,承担起社会责任,造福于环境和社会。  相似文献   

Surface and profile soil moisture spatio-temporal analysis during an excessive rainfall period in the Southern Great Plains,USA   总被引：1，自引：0，他引：1  

Gary C. Heathman  Myriam Larose  Michael H. Cosh  Rajat Bindlish 《CATENA》2009

In this work we analyze the temporal stability of soil moisture at the field and watershed scales in the Little Washita River Experimental Watershed (LWREW), as part of the remote sensing Cloud and Land Surface Interaction Campaign (CLASIC07) during June 2007 in south-central Oklahoma. Temporal stability of surface and profile soil moisture data were investigated for 20 LWREW soil moisture measurement stations. In addition, daily surface and profile soil moisture measurements were obtained in four 800 m by 800 m fields (remote sensing footprint), including two rangeland sites and two winter wheat fields. The work aimed to analyze the temporal stability of soil moisture at the watershed and field scale and to identify stations within the watershed, as well as locations within each field, that were representative of the mean areal soil moisture content. We also determined the relationship between sites found to be temporally stable for surface soil moisture versus those determined stable for average profile soil moisture content. For the unusually wet experimental period, results at the watershed scale show that LWREW stations 133 and 134 provided stable underestimates, while stations 132 and 154 provided stable overestimates of the watershed mean at all depths. In addition, station 136 had very high non-zero temporal stability at the 25 cm and 45 cm depths indicating that it could be used as representative watershed site provided a constant offset value is used to acquire a watershed mean soil water content value. In general, the deeper depths exhibited higher soil moisture spatial variability, as indicated by the higher standard deviations. At the field scale, measured average profile soil moisture was higher in the winter wheat fields than the rangeland fields with the majority of the winter wheat depth intervals having high non-zero temporal stability. Field scale temporal stability analysis revealed that 4 of the 16 sampling sites in the rangeland fields and 3 of the 16 sampling sites in the winter wheat fields either under or overestimated the field means in the 0–5 and 0–60 cm depth intervals. Field sites considered temporally stable for the surface soil moisture were not stable for the profile soil moisture, except for the LW45 field where two sites were stable at both the surface and profile soil moisture. This finding is significant in terms of soil moisture ground-truth sampling for calibrating and validating airborne remotely sensed soil moisture products under extremely wet conditions. In addition, identification of temporally stable sites at the watershed and field scales in the LWREW provide insight in determining future measurement station locations and field scale ground sampling protocol, as well as providing data sets for hydrologic modeling.  相似文献   

Prevalence and risk factors associated with Cryptosporidium spp. infection in young domestic livestock in India     

Prem Sagar Maurya  Radhamma Lakshmipathy Rakesh  Balaraju Pradeep  Saroj Kumar  Krishnendu Kundu  Rajat Garg  Hira Ram  Ashok Kumar  Partha Sarathi Banerjee 《Tropical animal health and production》2013,45(4):941-946

A total of 938 faecal samples (461 cattle calves, 264 buffalo calves, 55 lambs, 116 kids and 42 piglets) from different livestock farms and individual small holdings in six targeted states of India were collected and screened by modified Ziehl–Neelsen staining technique to determine the prevalence of Cryptosporidium spp. and its association with age, sex, season and faecal consistency in domesticated animals. Overall, 16.2 % of the animals were positive for Cryptosporidium infection with prevalence of 16.3, 24.2, 1.8, 3.5 and 19.1 % in cattle calves, buffalo calves, lambs, kids and piglets, respectively. The prevalence of infection was significantly higher (p?<?0.05) in bovines (19.3 % cattle and 33.7 % buffalo) below 1 month of age than in animals between 1 and 3 months of age. But in piglets, it was higher in the age group of 1 to 3 months (22.6 %) than in younger animals (9.1 %). Also, higher prevalence (p?>?0.05) was recorded in females than in males. Seasons had a significant effect (p?<?0.05) on the prevalence of infection in large ruminants, with the highest prevalence in monsoon (cattle 28.8 % and buffalo 36.6 %) followed by pre-monsoon and post-monsoon season. However, in case of sheep and goats, the prevalence was higher (p?>?0.05) in post-monsoon than in monsoon season. A high degree of association was noticed between Cryptosporidium infection and diarrhoea in ruminants screened during the present study. But, in case of pigs, the prevalence was higher in non-diarrhoeic than in diarrhoeic animals. Genotyping of Cryptosporidium spp. based on nested PCR amplification of partial 18S rRNA and its subsequent digestion with SspI, VspI and MboII restriction enzymes revealed prevalence of Cryptosporidium parvum in representative number of positive samples of cattle, buffalo and goats.  相似文献   

The effect of entrepreneurial and learning orientations on financial performance in a transition economy: evidence from forest contracting firms in southern Poland     

Adam Tomasz Sikora  Erlend Nybakk  Rajat Panwar 《Scandinavian Journal of Forest Research》2016,31(1):119-125

This study examines the role of entrepreneurial orientation (EO) and learning orientation (LO) in the financial success of forest contracting firms. Both EO and LO have previously been understood to positively affect a firm's financial performance, but extant literature has not considered those links in a transition economy. Partially addressing this gap, we execute this study in a Polish context. Using data obtained through a mail survey of 101 owners of forest contracting firms (34% response rate), we found that both EO and LO have a positive and significant effect on financial performance.  相似文献   

基于POE的动力学建模与快速非奇异终端滑模控制   总被引：1，自引：0，他引：1  

陈庆诚  朱世强  Rajat Mittal  张学群 《农业机械学报》2015,46(6):310-318

结合旋量指数积形式(POE)和凯恩方程的优点,提出了一种具有明显几何意义的高效动力学建模方法,并以此为基础提出机器人系统的快速非奇异终端滑模控制算法。凯恩方程中的偏速度选择为基于旋量理论描述的合适的物体雅可比矩阵,并以此定义其他动力学模型参数表达方式,且在"钱江一号"串联机器人上进行建模实例验证。基于该动力学模型,为了改善传统滑模控制的有限时间收敛特性,保证全局控制非奇异性,提出了一种快速全局非奇异终端滑模控制,通过构造带状态高次项的滑模面函数,得到全局非奇异控制,并保证系统从任意状态到达滑模面的时间和在滑模上到达平衡点的时间均为有限且快速收敛,通过李雅普诺夫函数证明了其稳定性,并结合对比实验,验证了该方法在机器人系统中的鲁棒性和有效性。  相似文献