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1.
C. Grenier P.J. Bramel J.A. Dahlberg A. El-Ahmadi M. Mahmoud G.C. Peterson D.T. Rosenow G. Ejeta 《Genetic Resources and Crop Evolution》2004,51(5):489-500
Sorghum [Sorghum
bicolor (L.) Moench] is a very important crop in the Sudan serving as a primary source of food, beverage, and total livelihood for millions of people in the country. The crop originated in the Northeast quadrant of Africa, and the Sudan is widely recognized as a major center of diversity. Although Sudanese sorghum germplasm has been assembled and stored over the last 50 years, careful analysis of this valuable germplasm has not been made. The objectives of this study were to assess phenotypic diversity and compare pattern of distribution among Sudanese sorghum landraces collected from different geographical regions. Phenotypic diversity among landraces was high, as expressed by the large range of variation for mean quantitative traits and the high (0.81) Shannon-Weaver diversity index. Landraces from Gezira-Gedarif tended to be shorter in stature, earlier in maturity and less sensitive to changes in photoperiod. They also had long, narrow and compact panicles that may result from adaptation to low rainfall and early adoption of mechanized farming practices. In contrast, taller and later maturing plant types characterized sorghums from Equatoria, most of which delayed their flowering in response to increased day-length. These sorghums included many genotypes with small and light kernels. Collections from Kassala showed a higher frequency of landraces with kernels that were more difficult to thresh. Landraces from Blue Nile tended to have greater agronomic eliteness with higher proportion of landraces with white kernels, poorly covered and that were easy to thresh. Sorghums from the Upper Nile tended to have loose panicles with poorly covered kernels that may result from adaptation to high rainfall of the Southern region. Although distinct distributions of types were represented by geographical origin, a high level of within-region diversity was present among all Sudanese sorghums. 相似文献
2.
Baye Berihun Getahun 《Journal of Crop Science and Biotechnology》2018,21(3):269-281
In this review, the genetic potential and efforts made on different aspects of potato breeding for nitrogen-use efficiency (NUE) and the possible physiological and genetic mechanisms determining NUE in potato in relation to other model crops are presented. Strategies to utilize the diverse gene pool of potato and improve the NUE in contrasting N environments are currently evaluated under field conditions using different selection approaches. So far, focused efforts have been made on the identification of potato genotypic differences which will allow for the analysis of specific components of nitrogen-use efficiency and the effect of nitrogen fertilizer on a range of physiological processes and morphological traits of potato. To my knowledge, despite the availability of genome sequence and QTLs identified for NUE and related agronomic and physiological traits in potato, and genomic information from other model crops, candidate genes on NUE have not yet been identified in potato. To maximize the success rate of potato breeding for NUE, basic knowledge how plants respond to different N regimes and other environmental conditions and use of DNA marker technology are vital. 相似文献
3.
Tesfaye Tesso Gebisa Ejeta Arun Chandrashekar Chia‐Ping Huang Agung Tandjung Mamadou Lewamy John D. Axtell Bruce R. Hamaker 《Cereal Chemistry》2006,83(2):194-201
Development of high‐protein digestibility (HPD)/high‐lysine (hl) sorghum mutant germplasm with good grain quality (i.e., hard endosperm texture) has been a major research objective at Purdue University. Progress toward achieving this objective, however, has been slow due to challenges posed by a combination of genetic and environmental factors. In this article, we report on the identification of a sorghum grain phenotype with a unique modified endosperm texture that has near‐normal hardness and possesses superior nutritional quality traits of high digestibility and enhanced lysine content. These modified endosperm lines were identified among F6 families developed from crosses between hard endosperm, normal nutritional quality sorghum lines, and improved HPD/hl sorghum mutant P721Q‐derived lines. A novel vitreous endosperm formation originated in the central portion of the kernel endosperm with opaque portions appearing both centrally and peripherally surrounding the vitreous portion. Kernels exhibiting modification showed a range of vitreous content from a slight interior section to one that filled out to the kernel periphery. Microstructure of the vitreous endosperm fraction was dramatically different from that of vitreous normal kernels in sorghum and in other cereals, in that polygonal starch granules were densely packed but without the typically associated continuous protein matrix. We speculate that, due to the lack of protein matrix, such vitreous endosperm may have more available starch for animal nutrition, and possibly have improved wet‐milling and dry‐grind ethanol processing properties. The new modified endosperm selections produce a range that approaches the density of the vitreous parent, and have lysine content and protein digestibility comparable to the HPD/hl opaque mutant parent. 相似文献
4.
Kean EG Ejeta G Hamaker BR Ferruzzi MG 《Journal of agricultural and food chemistry》2007,55(7):2619-2626
Sorghum is a critical source of food in the semiarid regions of sub-Saharan Africa and India and a potential source of dietary phytochemicals including carotenoids. The objective of this study was to determine the carotenoid profiles of sorghum cultivars, selected on the basis of their yellow-endosperm kernels, at various developmental stages. Following extraction from sorghum flours, carotenoids were separated by high-performance liquid chromatography (HPLC) with diode array detection. Total carotenoid content in fully matured yellow-endosperm sorghum kernels (0.112-0.315 mg/kg) was significantly lower (p < 0.05) than that in yellow maize (1.152 mg/kg) at physiological maturity. Variation in total carotenoids and within individual carotenoid species was observed in fully mature sorghum cultivars. For developing kernels, large increases in carotenoid content occurred between 10 and 30 days after half bloom (DAHB), resulting in a peak accumulation between 6.06 and 28.53 microg of total carotenoids per thousand kernels (TK). A significant (p < 0.05) decline was noted from 30 to 50 DAHB, resulting in a final carotenoid content of 2.62-15.02 microg/TK total carotenoids. (all-E)-Zeaxanthin was the most abundant carotenoid, ranging from 2.22 to 13.29 microg/TK at 30 DAHB. (all-E)-Beta-carotene was present in modest amounts (0.15-3.83 microg/TK). These data suggest the presence of genetic variation among sorghum cultivars for carotenoid accumulation in developing and mature kernels. 相似文献
5.
Amare Getahun 《Agricultural Systems》1978,3(4):281-293
Ethiopia is basically an agricultural and pastoral country. Agriculture dominates the Ethiopian life to the extent that little progress can be made unless agriculture is attacked directly. Ethiopia is a country of peasants with primitive agriculture. The physical potential for sharply increased agriculture is high but the obstacles for development are immense still, despite recent government attempts.The two dominant agricultural systems in Ethiopia are the mixed agriculture of the highlands, where both crops and livestock production are integrated, and pastoralism in the lowlands. The mixed agriculture exhibits several subsystems. Commercial agriculture using the river basins, such as the Awash Basin, is a recent phenomenon.Agricultural research as a formal activity and national programme is less than twenty-five years old and has undergone three formative stages reflecting the level of government commitment to agricultural development. The agricultural research system has now entered a new period where policy and infrastructures are being well laid down with emphasis on rural development. But these developments must be matched by greatly improved human and financial resource allocations. 相似文献
6.
1. Two experiments were conducted to determine the effects of tannins on nutrient utilisation in the White Pekin duck. 2. Experiment 1 was a rapid nutrient balance assay to determine the nitrogen (N) retention and metabolisable energy (ME) of maize, low-tannin sorghum (P-954063) (Sorghum bicolor (L). Moench) and high-tannin sorghum (IS-4225) cultivars for ducks. The assay lasted 120 h, with an initial 24 h food-deprivation period, a 48 h excreta collection period for endogenous losses and a 48 h excreta collection period for ingredient losses. The true metabolisable energy (TMEn) content was lower (P<0.05) in the high-tannin sorghum cultivar (13.85 MJ/kg) than the maize (14.94 MJ/kg) and the low-tannin sorghum cultivar (14.39 MJ/kg). True N retention was lower (P<0.05) for the high-tannin sorghum (0.24 g) than for maize (1.33 g) and low-tannin sorghum (1.1 g). 3. In experiment 2, the brush-border membrane vesicles technique was used to determine whether tannic acid caused inhibition of L-threonine transport across duck intestinal brush-border membrane. The brush-border membrane vesicles were mixed with tannic acid solutions (pH 7.4) to give gradient tannic acid concentrations of 0, 0.05, 0.10, 0.25, 0.50, 1.00 and 2.50%. As a fraction of the control (no tannic acid), the maximal inhibition of L-threonine transport (Imax) under the sodium-gradient condition was 77.10% (P<0.05). Under the sodium-free condition, the maximal inhibition of L-threonine transport (Imax) was 45.15% (P<0.05). 4. These results demonstrated that nutrient utilisation in the White Pekin duck was lower from the high-tannin sorghum cultivar than from the low-tannin sorghum cultivar. The results also suggested that the antinutritive effects of tannins in foodstuffs are due partly to their inhibitory action on intestinal brush-border bound amino acid transporter proteins. 相似文献
7.
Tuberculosis (TB) is an important zoonosis affecting a wide range of hosts. An abattoir study was conducted on 1,536 randomly
selected male goats slaughtered at Modjo Modern Export Abattoir to determine the prevalence of tuberculosis in slaughtered
goats. Carcasses and organs of all the study animals were first examined by routine meat inspection followed by detailed meat
inspection. Samples from tuberculous lesions were cultured for mycobacterial isolation and identification. Histopathology
was done on 31 samples with tuberculous lesions. Detailed meat inspection detected 65 (4.2%; 95% confidence interval (CI) = 3.3–5.4%)
tuberculous lesions. From these, 20 (30.8%) samples were confirmed mycobacterium positive on culture, out of which 18 were
Mycobacterium bovis and two were Mycobacterium tuberculosis. Routine meat inspection failed to detect tuberculous lesions in 23% of carcasses with TB lesions detected by detailed examination.
However, no statistically significant difference was observed between both methods in detecting tuberculous lesions (Kappa = 0.87).
Origin and age of the goats did not statistically affect the disease prevalence (P > 0.05). Histopathologic lesions were observed in 21 samples (68%; 95% CI = 50.1–81.4%) out of the 31 carcasses with gross
tuberculous lesions examined by histopathology. Eighteen (58%) tuberculous samples positive for histopathology were also culture
positive. The sensitivity and specificity of histopathology were 90% (95% CI = 76.9–100%) and 72.7% (95% CI = 46.4–99%), respectively,
using culture as a reference test. To the best of our knowledge, this is the first report of caprine tuberculosis from Ethiopia.
Further studies are required at the farm level to determine the prevalence of tuberculosis in the general goat population. 相似文献
8.
9.
Striga hermonthica (Del.) Benth., a parasitic weed of grasses, causes major yield reductions in the principal cereal crops of semi-arid Africa. Cultivar resistance is the most economic control measure, since adapted, resistant cultivars can be grown without additional input from the subsistence farmer. Information on the genetics of resistance to S. hermonthica is scant. This is partially attributable to the rarity of germplasms which exhibit stable resistance across geographical regions. The objective of this study was to determine if the stable resistance observed in sorghum [Sorghum bicolor (L.) Moench] cultivar SRN39 is heritable. Crosses were made between SRN39 and a susceptible parent, P954063. Parental, F1, F2 and backcross generations were grown in infested pots and development of both host and parasite was monitored. Significant variation among genotypes was observed for both host traits and effects on parasite populations. The F1 did not differ significantly in Striga resistance from the susceptible parent, suggesting recessive inheritance. However, hybrid vigor was exhibited by the F1 which yielded and developed as well as the resistant parent. Broad sense heritability ranged from 0.23 to 0.55 for host traits and from 0.10 to 0.43 for effect of genotypes on the Striga population. Joint scaling tests showed that observed variation in each host or parasite trait consisted of additive and dominance components, suggesting possible progress could be made with appropriate selection schemes. 相似文献
10.
Legesse Getahun Siegmund-Schultze Marianna Abebe Girma Valle Zárate Anne 《Tropical animal health and production》2010,42(7):1531-1539
This study evaluates the household income contribution and the profitability of traditional small ruminant enterprises in
two mixed-farming systems of southern Ethiopia (viz. Adilo and Kofele). Small ruminant production is an integral part of mixed systems in the Ethiopian highlands. The assessment
of the current economic performance of small ruminants indicates production-related opportunities and constraints and provides
baseline data against which the success of future interventions can be measured. Detailed information on economic parameters
was gathered through a 1-year period of flock and household monitoring (155 households) between September 2005 and August
2006. Structured surveys were conducted with the participating households to elicit information on income-expense details
of small ruminant and other agricultural enterprises. Small ruminants contributed considerably to cash income and to a limited
extent to human nutrition especially when other sources were in short supply. The annual profit per animal ranged from 20
to 37 Ethiopian Birr. The return to capital was 17% in Kofele and 29% in Adilo, with both values vastly exceeding the national
interest rate. The sale of small ruminants contributed to 39% and 23% of total farm cash income among small ruminant keepers
in Adilo and Kofele, respectively. Sale prices are highest before holidays. Researches should target at how to use available
feed resources in a timely and cost-effective fashion to make use of the seasonal market opportunities. 相似文献