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91.
Adhikari TB Cavaletto JR Dubcovsky J Gieco JO Schlatter AR Goodwin SB 《Phytopathology》2004,94(11):1198-1206
ABSTRACT Breeding wheat for resistance is the most effective means to control Septoria tritici blotch (STB), caused by the ascomycete Mycosphaerella graminicola (anamorph Septoria tritici). At least eight genes that confer resistance to STB in wheat have been identified. Among them, the Stb4 locus from the wheat cv. Tadinia showed resistance to M. graminicola at both seedling and adult-plant stages. However, no attempt has been made to map the Stb4 locus in the wheat genome. A mapping population of 77 F10 recombinant-inbred lines (RILs) derived from a three-way cross between the resistant cv. Tadinia and the susceptible parent (Yecora Rojo x UC554) was evaluated for disease resistance and molecular mapping. The RILs were tested with Argentina isolate I 89 of M. graminicola for one greenhouse season in Brazil during 1999, with an isolate from Brazil (IPBr1) for one field season in Piracicaba (Brazil) during 2000, and with Indiana tester isolate IN95-Lafayette-1196-WW-1-4 in the greenhouse during 2000 and 2001. The ratio of resistant:susceptible RILs was 1:1 in all three tests, confirming the single-gene model for control of resistance to STB in Tadinia. However, the patterns of resistance and susceptibility were different between the Indiana isolate and those from South America. For example, the ratio of RILs resistant to both the Indiana and Argentina isolates, resistant to one but susceptible to the other, and susceptible to both isolates was approximately 1:1:1:1, indicating that Tadinia may contain at least two genes for resistance to STB. A similar pattern was observed between the Indiana and Brazil isolates. The gene identified with the Indiana tester isolate was assumed to be the same as Stb4, whereas that revealed by the South American isolates may be new. Bulked-segregant analysis was used to identify amplified fragment length polymorphism (AFLP) and microsatellite markers linked to the presumed Stb4 gene. The AFLP marker EcoRI-ACTG/MseI-CAAA5 and microsatellite Xgwm111 were closely linked to the Stb4 locus in coupling at distances of 2.1 and 0.7 centimorgans (cM), respectively. A flanking marker, AFLP EAGG/ M-CAT10, was 4 cM from Stb4. The Stb4 gene was in a potential supercluster of resistance genes near the centromere on the short arm of wheat chromosome 7D that also contained Stb5 plus five previously identified genes for resistance to Russian wheat aphid. The microsatellite marker Xgwm111 identified in this study may be useful for facilitating the transfer of Stb4 into improved cultivars of wheat. 相似文献
92.
93.
Abdelmagid OY Larson L Payne L Tubbs A Wasmoen T Schultz R 《Veterinary therapeutics : research in applied veterinary medicine》2004,5(3):173-186
The results of this study confirmed that dogs vaccinated subcutaneously with a commercially available multivalent vaccine containing modified-live canine distemper virus, canine adenovirus type 2, canine parvovirus type 2b, and canine parainfluenza virus antigens were protected against sequential experimental challenge 55 to 57 months after initial vaccination given at 7 to 8 weeks of age. All 10 vaccinates were protected against clinical diseases and mortality following parvovirus and infectious canine hepatitis experimental infections. All vaccinates were protected against mortality and 90% against clinical disease following distemper challenge. These data support at least a 4-year duration of immunity for these three "core" fractions in the combination vaccine. 相似文献
94.
During 2010, yellowing symptoms were frequently observed in cultivated squash fields in Egypt. A total of 717 symptomatic
squash leaf samples were collected from four regions where squash cultivation is of economic importance for the country: Kafrelsheikh,
El-Behira, El-Sharkia and El-Ismailia. Serological analysis showed that 95.6% of the symptomatic squash samples were infected
by Cucurbit aphid-borne yellows virus (CABYV), and visual estimation of the incidence of yellowing symptoms suggested a very high incidence of CABYV in the fields.
Twelve CABYV isolates were characterized by sequencing two regions of the viral genome, open reading frame (ORF) 3 and ORFs
4/5. Overall, Egyptian isolates were very similar among them, and had higher similarity values with a French than with a Chinese
isolate. The average nucleotide diversity for ORF 3 was significantly higher than for the other two regions, indicating that
variability is not evenly distributed along the viral genome. The ratios between nucleotide diversity values in non-synonymous
(d
N
) and synonymous (d
S) positions (d
N
/d
S) for each ORF showed that the three ORFs are evolving under different pressures, although predominantly under purifying selection.
Phylogenetic analyses revealed that these Egyptian isolates, with only one exception, shared the same clade with a French
isolate. Moreover, these analyses suggested that Egyptian isolates belong to the Mediterranean group described previously. 相似文献
95.
96.
Song M Che TM Liu Y Soares JA Harmon BG Pettigrew JE 《Journal of animal science》2012,90(9):3080-3087
Four experiments were conducted to evaluate the nutrient contributions and physiological health benefits of spray-dried egg (SDE) containing only unfertilized eggs as a protein source in nursery pig diets. In all experiments, all diets were formulated to the same ME and Lys content, and each pen within a block (by BW) housed the same number of barrows and gilts. In Exp. 1 and 2 (168 and 140 pigs, respectively; 5 kg BW; 16 d old; 14 replicates/experiment), conducted at a university farm, treatments were with or without 5% SDE in a nursery control diet, which included antibiotics and zinc oxide. Pigs were fed for 10 d after weaning to measure ADG, ADFI, and G:F. The SDE increased (P < 0.05) ADG (Exp. 1: 243 vs. 204 g/d; Exp. 2: 204 vs. 181 g/d) and ADFI (Exp. 1: 236 vs. 204 g/d; Exp. 2: 263 vs. 253 g/d) compared with the control diet but did not affect G:F. In Exp. 3 (1,008 pigs; 5.2 kg BW; 20 d old; 12 replicates/treatment), conducted at a commercial farm, treatments were in a factorial arrangement of with or without SDE and high or low spray-dried plasma (SDP) in nursery diets, which included antibiotics and zinc oxide. Pigs were fed for 6 wk using a 4-phase feeding program (phases of 1, 1, 2, and 2 wk, respectively) with declining diet complexity to measure ADG, ADFI, G:F, removal rate (mortality plus morbidity), and frequency of medical treatments per pen and day (MED). The diets with the SDE increased (P < 0.05) ADFI during phase 1 only (180 vs. 164 g/d) compared with the diets without the SDE but did not affect growth performance during any other phases. The diets with SDE reduced MED during phase 1 (0.75% vs. 1.35%; P < 0.05) and the overall period (0.84% vs. 1.01%; P = 0.062) compared with the diets without the SDE but did not affect removal rate. In Exp. 4 (160 pigs; 6.7 kg BW; 21 d old; 10 replicates/treatment), conducted at a university farm to determine whether SDE can replace SDP, treatments were in a factorial arrangement of with or without SDP or SDE in nursery diets, which excluded antibiotics and zinc oxide. Pigs were fed for 6 wk using the same schedule used in Exp. 3 to measure ADG, ADFI, and G:F. The diets with SDE increased (P < 0.05) ADFI during phase 1 only (195 vs. 161 g/d) compared with the diets without SDE but did not affect growth performance during any other periods. In conclusion, SDE can be an efficacious protein and energy source in nursery pig diets and improves health and, in some instances, increases growth rate. 相似文献
97.
甜菜素是一种重要的天然色素,具有广阔的应用前景。为探究调控甜菜素合成关键基因BvDDC1功能,本研究测定了不同生长阶段甜菜‘Yellow chard’的甜菜素含量和BvDDC1的相对表达量,同时采用同源克隆技术获得BvDDC1基因序列,并对其进行生物信息学分析及功能预测。结果表明:甜菜叶片中甜菜素含量随甜菜生长时间的延长呈现上升趋势,且BvDDC1在不同时期甜菜叶片中均有表达,呈现先上升后下降的趋势。甜菜素含量越高,BvDDC1表达量越高。BvDDC1序列全长为1509 bp,编码502个氨基酸,编码蛋白不具有跨膜结构,预测其在膜外发挥作用。系统进化树显示与菠菜亲缘关系较近,同源性最高。本研究结果可为解析甜菜素生物合成提供科学依据。 相似文献
98.
由于桥面铺装在施工经验及施工工艺上的不足,使得桥面铺装在施工过程中常出现一些质量通病。本文结合苇河林业局冲河林场公路桥桥面铺装施工的实例,介绍了在桥面铺装施工中建立施工保证体系和工序管理体系的重要性,并提出了质量目标要求及采取的相应质量管理措施。 相似文献
99.
100.
Small-scale forestry-based enterprises connected with wood processing are becoming of growing importance in the rural economy of developing countries. Little attention has been paid to the characteristics of these enterprises and their role in supporting economic development. The objectives of this study are to: (1) determine the socioeconomic characteristics of the operators of these enterprises; (2) assess the contribution of the informal carpentry sector to operators’ income; and (3) identify the factors limiting the expansion of the sector. The study was carried out in the Singa district, Sinnar State in 2011. Snowball sampling was used to select 250 operators from five markets in the district. The quantitative and qualitative data were collected using Participatory Rural Appraisal methods. The results revealed that most operators involved in the informal carpentry sector are males aged <30 years and their businesses have been in existence for <10 years. Operators’ incomes ranged between USD 100 and 500 monthly on average. The results also indicated that the operators face many constraints (e.g. finance shortage, lack of raw materials, insecure market, lack of technology and lack of organization) to expanding the informal carpentry sector. The study concluded that the informal carpentry sector has potential to contribute to rural economic development through increasing income and reducing rural poverty. 相似文献