Causes of negative correlations between grain yield and grain protein concentration in common wheat   总被引：7，自引：0，他引：7  

Solomon Kibite  L. E. Evans 《Euphytica》1984,33(3):801-810

Summary In a study designed to investigate the nature and basis of the relationships between grain yield (GY) and grain protein concentration (GBC) in common wheat, 11 populations, including 4 homozygous-homogeneous and 7 heterozygous-heterogeneous populations, were evaluated in a space planted and a solid seeded trial. Analysis of yield and protein data from each population revealed that phenotypic and environmental correlations between GY and GPC were negative and highly significant, whereas genetic correlation was significant in only one of 7 segregating populations studied. These results suggested that the inverse relationships between GY and GPC, although phenotypically real, were not caused by genetic factors. It would appear that environmental factors, source-sink interactions, and dilution of protein by non-protein compounds were the major agents that caused undesirable associations between the two traits.Contribution No. of the Department of Plant Science, University of Alberta, Edmonton, Alberta, Canada T6G2P5  相似文献   

Farmers’ perception and reasons for practicing farmer managed natural regeneration in Tigray,Ethiopia     

Kibru  Tigist  Husseini  Rikiatu  Birhane  Emiru  Haggar  Jeremy  Solomon  Negasi 《Agroforestry Systems》2021,95(7):1327-1342

Agroforestry Systems - Farmer Managed Natural Regeneration (FMNR) is a rapid, low cost and easily replicated approach to restore and improve degraded agricultural, forest and pasture lands. The...  相似文献   

Effects of hot dry summers on the loss of Atlantic salmon, Salmo salar, from estuaries in South West England     

D. J. Solomon  & H. T. Sambrook 《Fisheries Management and Ecology》2004,11(5):353-363

Salmon, Salmo salar L., were radio tagged in four estuaries in South West England. At medium to high summer flows, most salmon entering the river did so within 10 days of tagging. Lower flows were associated with an increased tendency for fish to remain in tidal water for a protracted period, and for those delayed fish to fail to enter the river. The delay was correlated with low freshwater flow, but it was concluded that high water temperature, and in some situations low dissolved oxygen, were likely to be the major influences. The causes of failure to enter the river by the delayed fish include lethally low levels of oxygen in some situations, but a major factor may be missed physiological opportunity. Implications in terms of water resource management, fisheries management and climate change are discussed.  相似文献   

Changes in climatic water balance drive downhill shifts in plant species' optimum elevations     

Crimmins SM  Dobrowski SZ  Greenberg JA  Abatzoglou JT  Mynsberge AR 《Science (New York, N.Y.)》2011,331(6015):324-327

Uphill shifts of species' distributions in response to historical warming are well documented, which leads to widespread expectations of continued uphill shifts under future warming. Conversely, downhill shifts are often considered anomalous and unrelated to climate change. By comparing the altitudinal distributions of 64 plant species between the 1930s and the present day within California, we show that climate changes have resulted in a significant downward shift in species' optimum elevations. This downhill shift is counter to what would be expected given 20th-century warming but is readily explained by species' niche tracking of regional changes in climatic water balance rather than temperature. Similar downhill shifts can be expected to occur where future climate change scenarios project increases in water availability that outpace evaporative demand.  相似文献   

Breeding practices,growth, and carcass potential of fat-tailed Washera sheep breed in Ethiopia     

Getachew T  Gizaw S  Lemma S  Taye M 《Tropical animal health and production》2011,43(7):1443-1448

On-farm survey of farmers' breeding practices, breeding objectives, and selection criteria and on-station feedlot performance evaluation of Washera sheep were undertaken in Ethiopia. The survey revealed that most (79.8%) of the farmers had no breeding ram. The mating system was predominantly uncontrolled. A majority (75.5%) of the sheep owners reported that they herded their sheep flock by mixing with other livestock species mainly with cattle. During grazing, 44.6% of the farmers mix their sheep flock with neighboring sheep flocks. The major sheep production objective was to generate income from the sale of live sheep. Fast growth, appearance, coat color, and pedigree performance were important ram selection criteria, respectively. Ability to breed at early age, pedigree information, mothering ability, and lambing interval were important selection criteria for ewe, respectively. The on-station performance study involved evaluation of feedlot gains and carcass production under five levels of feeding regimes (300, 400, 500, 600, and 700 g day⁻¹ of concentrate feed) for a period of 93 days. The results indicated that the feedlot growth and carcass performance of Washera sheep were very high, with average daily weight gains of up to 126 g and carcass weight of 16 kg, with the optimal level of supplementation for Washera sheep being at 500 g of concentrate per day for a period of 93 days.  相似文献   

H-ras consensus sequence and mutations in primary hepatocellular carcinomas of lemurs and lorises     

Cullen JM  Williams C  Zadrozny L  Otstot JT  Solomon GG  Sills RC  Hong HH 《Veterinary pathology》2011,48(4):868-874

The authors have determined a consensus sequence for exons 1 and 2 of H-ras from captive lemurs and lorises and evaluated samples of nonneoplastic liver and hepatocellular carcinomas (HCC) from affected animals for mutations in these exons. Frozen liver samples were collected from 20 animals representing 9 different species with a sex distribution of 10 males and 10 females. A total of 26 liver samples, including 11 normal livers, 9 HCC, and 6 samples from nonneoplastic regions of liver from animals with HCC, were evaluated. This is the first report of the consensus sequence for exons 1 and 2 of H-ras in prosimians, and the authors have determined that it is identical to that of human H-ras and differs only slightly from the chimpanzee sequence. Point mutations were identified in 6 of the 9 HCC samples examined with codons 7, 22, 32, 56, 61, 84, and 96 affected. Two carcinomas had double mutations, and one tumor had triple mutations. One HCC had a mutation in codon 61, which is identical to a recognized affected codon for an H-ras "hot spot" in rodent neoplasia that has also been reported in human tumors. Although not statistically different, metastasis occurred in 5 of 6 HCC with H-ras mutation and only 1 of 3 HCC without mutations. There were 4 silent mutations that did not contain changes in the encoded amino acids, 2 of which were found in nonneoplastic regions of tumor-bearing liver.  相似文献   

Effect of a single injection of adrenaline on shell ultrastructure in a series of eggs from domestic hens   总被引：1，自引：0，他引：1  

S E Solomon  B O Hughes  A B Gilbert 《British poultry science》1987,28(4):585-588

1. Adrenaline (1 mg in 1 ml water) was administered subcutaneously to three hens to determine whether any changes in the shell ultrastructure of subsequent eggs would occur. 2. The egg shells were examined in a scanning electron microscope after plasma etching. 3. The first three eggs laid by each bird after adrenaline injection were compared with previously-collected normal eggs from the same birds and also with control eggs collected over the same period from three hens which had received no adrenaline. 4. The first egg laid following adrenaline treatment was essentially normal but both the second and third eggs showed severe structural disorganisation at all levels, from the mamillary caps up to the cuticular layer. 5. Eggs laid 20 d or more after adrenaline treatment had reverted to normal. 6. The findings suggest that the abnormal eggs laid after hens have been exposed to disturbance or stress are likely to be affected in not only their external appearance but also to be of poor structural quality.  相似文献   

Response of low and high protein select lines of pigs to the feeding of the beta-adrenergic agonist ractopamine (phenethanolamine)   总被引：1，自引：0，他引：1  

A D Mitchell  M B Solomon  N C Steele 《Journal of animal science》1990,68(10):3226-3232

The effect of ractopamine, a phenethanolamine beta-adrenergic agonist, on growth, nutrient utilization and carcass composition was studied in two lines of pigs that were fed high (24%) or low (12%) protein diets. Of the two lines of pigs that had been selected for seven generations for rapid lean growth when fed either the higher (HS line) or low (LS line) protein diet, the HS line tended to exhibit a leaner carcass when fed either diet. Ractopamine, at 20 ppm in the diet, was fed from 60 kg live body weight until slaughter at 90 kg. When compared with their respective line-diet control group, the greatest response to ractopamine treatment was observed in the LS-12 group; at 90 kg, that group had 31% less carcass lipid (P less than .05) and 17% more carcass protein (P less than .05). Considering the change that took place only between 60 and 90 kg live body weight, this translated into 57% less lipid and 59% more protein deposited in the carcasses with ractopamine treatment. This group also was 73% more efficient (P less than .05) in converting dietary protein to carcass protein but 39% less efficient (P less than .05) in energy utilization. Response to ractopamine treatment was least by the LS-24 group, followed by the HS-12 and HS-24 groups. A line x diet x treatment interaction (P less than .05) was noted for whole-carcass lipid, backfat, longissimus muscle area and efficiency of protein utilization.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

Lipid composition of muscle and adipose tissue from crossbred ram, wether and cryptorchid lambs   总被引：3，自引：0，他引：3  

M B Solomon  G P Lynch  K Ono  E Paroczay 《Journal of animal science》1990,68(1):137-142

Lambs from rams (R), cryptorchids (C) and wethers (W) were examined to compare with the dietary guidelines for humans on fat and cholesterol intake. Twenty-four lambs were assigned to treatments as R, C or W at weaning (60 d). Each lamb had ad libitum access to a 77:23% forage:concentrate diet containing 11.7% crude protein and 1.84 Mcal ME/kg. The experiment was terminated when the lambs reached 50 kg body weight. Lipid composition of the longissimus muscle (LM) and s.c. adipose tissue was determined by gas-liquid chromatography. Rams has less (P less than .01) s.c. fat (cm) and i.m. lipid (%) (.26 cm; 3.*%) than W (.56 cm; 4.9%). Total polyunsaturated fatty acids were greater (P less than .01) in the LM of R (7.06%) than in LM of W (5.21%). Rams had higher percentages of C18:2, C18:3, C20:4 and C18:1 in their LM than W did. On the basis of a 100-g serving of LM, R had 1.73, C had 2.15 and W had 2.21 g saturated fatty acids. There were no (P less than .01) differences among sex types for cholesterol content of LM, which averaged 66.6 mg/100 g wet tissue. The only major difference of the s.c. fat lipid composition was in saturated fatty acids. Wethers had higher (P less than .01) saturated fatty acids (51.4%) than C 46.8%) and R (43.3%). Based on the lipid composition of these three types of lambs, the LM muscle from young R lambs approached dietary fat guidelines for humans more closely than did that from castrates.  相似文献   

Effects of different forms of white lupin (Lupinus albus) grain supplementation on feed intake,digestibility, growth performance and carcass characteristics of Washera sheep fed Rhodes grass (Chloris gayana) hay-based diets     

Gebru Tefera  Firew Tegegne  Yeshambel Mekuriaw  Solomon Melaku  Atsushi Tsunekawa 《Tropical animal health and production》2015,47(8):1581-1590

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