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371.
Flowering time has biological and agricultural significance for crops. In Upland cotton (Gossypium hirsutum L.), photoperiodic sensitivity is a major obstacle in the utilization of primitive accessions in breeding programs. Quantitative
trait loci (QTLs) analysis was conducted in two F2 populations from the crosses between a day-neutral cultivar Deltapine 61 (DPL61) and two photoperiod sensitive G. hirsutum accessions (T1107 and T1354). Node of first fruiting branch (NFB) was used to measure relative time of flowering. Different
flowering time genetic patterns were observed in the two populations. Two QTLs were found across five scoring dates, accounting
28.5 (qNFB-c21-1) and 15.9% (qNFB-c25-1) of the phenotypic variation at the last scoring date in Pop. 1107 (DPL61 by T1107); whereas, one major QTL (qNFB-c25-1) can be detected across five scoring dates, explained 63.5% of the phenotypic variation at the last scoring date in Pop.
1354 (DPL61 by T1354). QTLs with minor effects appeared at various scoring date(s), indicating their roles in regulating flowering
at a lower or higher node number. Genetic segregation analysis and QTL mapping results provide further information on the
mechanisms of cotton photoperiodic sensitivity.
Part of a Ph.D. dissertation by senior author submitted to the Department of Plant and Soil Sciences, Mississippi State University,
December 2007. Contribution of USDA-ARS in cooperation with the Mississippi Agric. and Forestry Exp. Stn. Journal paper J.
11276 of Mississippi Agric. and Forestry Exp. Stn. 相似文献
372.
J R Jenkins 《Veterinary Clinics of North America: Exotic Animal Practice》1999,2(1):143-51, vii
The feeding recommendations for the pet or house rabbit include grass hay fed ad libitum, dark leafy green vegetables fed at one cup per 5 pounds of body weight, and a maximum of 1 cup of high fiber pellets per 5 pounds of body weight. These recommendations are based on the feeding behavior, anatomy, and gastrointestinal physiology of the rabbit. Feeding this diet reduces the occurrence of common gastrointestinal tract disease in the house rabbit. This article reviews the feeding behavior, anatomy, and gastrointestinal physiology of the rabbit. 相似文献
373.
Andrew W. Claridge Douglas J. Mills Rob Hunt David J. Jenkins Josh Bean 《Forest Ecology and Management》2009
Satellite tracking was used to follow the movements of a problematic top-order carnivore, the wild dog (Canis lupus dingo, C. lupus familiaris and their hybrids), in contiguous forested landscapes in south-eastern mainland Australia. Home range sizes of wild dogs were much larger than previously determined using conventional telemetry methods, averaging 10,000 ha with a maximum size of 59,000 ha over approximate 3-month periods. Wild dogs at sites with high abundance of kangaroos, wallabies and rabbits had smaller areas of occupancy than did dogs at sites with low availability of these preys. Despite mostly large home ranges, tracked animals were loyal to publicly-owned tenure and there were few instances where individuals moved large distances on to adjacent private tenure. Instead, movement behaviours of most tracked animals were characterised by repeated short distance forays, often at acute angles from previous locations. Consequently, home ranges were stable and otherwise well defined. Analysis of DNA from our study animals indicated that most individuals were of ‘dingo’ ancestry, but otherwise considered hybrids because of the presence of domestic dog genes. Only two of 24 animals could be considered as ‘pure’ dingo. Contemporary wild dog management demarcates lands where control is or is not undertaken, with the latter notionally acting to ‘conserve’ dingoes. Due to the large scale of movement of animals, existing control efforts likely impact over a greater area than previously suspected. Furthermore, our genetic findings suggest that conservation of dingoes in south-eastern mainland Australia is difficult to achieve. A modified approach to wild dog management is needed, taking account of the extent of range of individual animals and the existing genetic characteristics of populations. 相似文献
374.
Earle-Richardson G Fulmer S Jenkins P Mason C Bresee C May J 《Journal of agricultural safety and health》2004,10(3):163-176
Although back, neck, and shoulder strains are common among migrant and seasonal orchard workers, little data currently exist regarding the ergonomic factors contributing to this problem. We adapted Posture-Activities-Tools-Handling (PATH) instruments and methods for ergonomic job analysis of apple harvest work in three New York orchards, and used the resulting protocol to quantify hazardous activities, loads, and postures. Using a prototype developed previously, we trained twelve contract orchard observers with classroom training and supervised orchard practice. The PATH data were then collected on 14 orchard workers over four days (2,900 observations). Mean coefficients of variation ranged from a low of 0.212 (standing leg neutral) to a high of 0.603 (trunk moderate flexion). Most frequently observed activities were: picking (62.9%), placing and moving apples in the bag (8. 7%), and walking (8.1%). Weight bearing (>10 lb, >4.54 kg) was observed 78.5% of the time throughout a range of activities. Apple harvest work is comparable with other ergonomically high-risk occupations. Future research should focus on low-cost interventions that reduce load and awkward postures. 相似文献
375.
Johnie N. Jenkins Jack C. McCartyJr. B. Todd Campbell R. W. Hayes Jixiang Wu Sukumar Saha David Stelly 《Euphytica》2017,213(5):107
Upland cotton, Gossypium hirsutum L. is the most widely planted cultivated cotton in the United States and the world. The other cultivated tetraploid species G. barbadense L. is planted on considerable less area; however, it produces extra long, strong, and fine fibers which spins into superior yarn. The wild cotton tetraploid species G. tomentosum Nuttall ex Seemann, native to the Hawaiian Archipelago also exhibits traits, such as drought tolerance, that would also be desirable to transfer to Upland cotton. Long-term breeding efforts using whole genome crosses between Upland and these species have not been successful in transferring very many desirable alleles into Upland cotton. Our chromosome substitution lines (CSL) have one chromosome or chromosome arm from an alien species backcrossed into the Upland cotton line,TM-1, via aneuploid technology. Five Upland cultivars were crossed with CS-B01, CS-T01, CS-B04, CS-T04, CS-B18 and CS-T18 and TM-1 the recurrent parent of the CSLs. This provided an opportunity to determine the effects of chromosomes 01, 04, and 18 from the three species in crosses with the five cultivars. Predicted genotypic mean effects of the parents, F2, and F3 generations for eight agronomic and fiber traits of importance were compared. The predicted hybrid mean effects for the three chromosomes from each species were different for several of the traits across cultivars. There was no single chromosome or species that was superior for all traits in crosses. Parental and hybrid lines often differed in the effect of a particular chromosome among the three species. The predicted genotypic mean effects for F2 and F3, with a few exceptions, generally agree with our previous results for additive and dominance genetic effects of these CSL. 相似文献
376.
U.S. Babu P.L. Wiesenfeld M.Y. Jenkins 《Plant foods for human nutrition (Dordrecht, Netherlands)》1998,53(2):169-174
The impact of rosemary extract on splenic mononuclear cell proliferation was determined. Weanling male Sprague-Dawley rats were fed diets containing 0, 100, 200 or 400 ppm rosemary extract or 400 ppm butylated hydroxytoluene (BHT) in combinatiion with 10 or 20% casein enriched diets for 8 weeks. Splenic mononuclear cells were isolated from these animals and mitogenic response to Concanavalin A (Con A), Phytohemagglutinin (PHA) and lipopolysaccharide was determined. Con A and PHA-stimulated proliferation of spleen cells from rats fed 10% casein and 200 ppm rosemary extract was significantly higher than that of cells from the corresponding control animals. However, other levels of rosemary at 10% dietary casein or rosemary at any concentration fed along with 20% dietary casein had no impact on the mitogenic stimulation of splenic mononuclear cells. Thus, these results suggest that the use of rosemary might not have a generalized immunoenhancing effect, and will probably be effective in some stressed conditions, such as protein or antioxidant deficiency. 相似文献
377.
Journal of Plant Diseases and Protection - Pine wood nematode (PWN), Bursaphelenchus xylophilus, causes pine wilt disease (PWD) in Pinus species given suitable climatic conditions. A model was run... 相似文献
378.
Nicholas T. Jenkins Gustavo Pe?a Carlos Risco Carolina C. Barbosa Achilles Vieira-Neto Klibs N. Galv?o 《The Canadian veterinary journal. La revue veterinaire canadienne》2015,56(8):850-854
The objective was to identify a fat-to-protein ratio (FPR) cut-off to diagnose subclinical ketosis (SCK) and to evaluate the effect of propylene glycol (PPG) treatment of cows with high FPR. The optimized cut-off was > 1.42; sensitivity (Se) = 92%; specificity (Sp) = 65%. A cut-off > 1.5 was selected for the PPG trial for balanced Se-Sp. Fat-to-protein ratio cut-offs > 1.25, 1.35, 1.50, 1.60, and 1.70 resulted in Se-Sp of 100% to 49%, 96% to 59%, 75% to 78%, 33% to 90%, and 8% to 96%, respectively. The proportions of cows with FPR > 1.25, 1.35, 1.42, 1.50, 1.60, and 1.70 were 60%, 50%, 44%, 30%, 14%, and 6%, respectively. Incidences of clinical ketosis and milk yield were similar between cows that received 400 mL of PPG (n = 34) and control cows (n = 38). Prevalence of SCK at enrollment was 29.2%; therefore, FPR > 1.5 is not indicated for treatment. Lower cut-offs should be used for screening. 相似文献
379.
The segregation of isozyme markers has been examined in the green and albino androgentic progenies of two plants of Lolium perenne. Overall the pooled data for the loci PG1/2 and GOT/2 does not deviate from expectation, but there is considerable heterogeneity between families and between green and albino plants. Specific alleles predominate in the different progeny sets. The results may be accounted for by possible linked loci affecting anther culture response or of linked lethal genes. 相似文献
380.
G. Jenkins 《Euphytica》1969,18(2):204-210
Summary Results of observations on grain shedding in spring oats are presented for the seasons 1966, 1967 and 1968. These observations were made in field studies and also in laboratory tests using specially designed equipment, which is described in detail.A delay in harvesting, of approximately one month, resulted in mean grain losses in field trials of 13 per cent in 1967 and 23 per cent in 1968. Large varietal differences in grain shedding were observed in laboratory tests. There was no correlation between the grain shedding of varieties in the laboratory and their grain loss in the field in 1967, when the latter was estimated from small samples but laboratory and field results were highly correlated, positively, in 1968 when field losses were estimated from whole plots.The relative performance of varieties in laboratory tests was not substantially affected by the period of storage of the material or by the severity of the test applied. The relative grain shedding of varieties in laboratory tests was similarly unaffected by the date of harvest of the material, provided that ripe samples were taken.The proportion of grain shed in laboratory tests was negatively correlated with time from sowing to panicle emergence in 1967 and 1968. In both seasons, however, some varieties of identical maturity were differentiated in their grain shedding tendencies.The application of the laboratory technique to the screening of breeding material is discussed. 相似文献