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Commercial Cultivars (commercial + cultivar)
Selected AbstractsFlavonoids in Onion Cultivars (Allium cepa L.)JOURNAL OF FOOD SCIENCE, Issue 8 2008B. Rodríguez Galdón ABSTRACT:, Total phenol and flavonoid contents were analyzed by HPLC coupled with a diode array detector in 5 traditional onion cultivars from Tenerife (Guayonje, San Juan de la Rambla, Carrizal Alto, Carrizal Bajo, and Masca) and a commercial cultivar (Texas Early Grano 502). Five quercetin chemical species (isoquercetin, quercetin diglucoside, quercetin monoglucoside 1, quercetin monoglucoside 2, and free quercetin) and kaempferol were identified and quantified in the onion samples. Quercetin monoglucoside 1 and quercetin diglucoside were the major flavonoids accounting for 80% of the total quercetin content. The mean quercetin monoglucoside 1: quercetin diglucoside ratio (QMG/QDG) was 1: 2.2. There were differences between the onion cultivars in the cases of total phenol, quercetin diglucoside, isoquercetin, QMG/QDG ratio, and kaempferol. The Texas cultivar had a higher QMG/QDG ratio and a higher kaempferol content than the traditional cultivars. The correlation study showed significant correlations between the analyzed phenolic components. [source] Isolation and characterization of microsatellite loci from a commercial cultivar of Musa acuminataMOLECULAR ECOLOGY RESOURCES, Issue 2 2006SILVANA CRESTE Abstract A genomic library from the commercial diploid cultivar ,Ouro' (Musa acuminata), enriched for CT- and GT-repeats, was used to isolate and characterize 23 microsatellite loci. These loci were tested in 10 Musa genotypes, representing various Musa genomic groups with distinct ploidy level. The number of alleles per locus ranged from one to seven, and 20 loci were highly informative. Four loci appeared to amplify B genome-specific alleles, while three loci seemed to be absent in the B genome. The polymorphism revealed by these loci will be extremely useful for genetic mapping, marker-assisted selection, germplasm characterization and evolutionary studies in Musa. [source] Seed variation among annual ryegrass cultivars in south-eastern USA and the relationship with seedling vigour and forage productionGRASS & FORAGE SCIENCE, Issue 4 2002B. C. Venuto Abstract Annual ryegrass (Lolium multiflorum Lam.) is grown on more than one million ha in the south-eastern USA each year. Recommended and actual seeding rates vary substantially within the region. The objective of this study was to evaluate variation in seed weight, germination, seedling vigour and seasonal yield performance among annual ryegrass cultivars. During 1997, 1998 and 1999, seed from fourteen commercial cultivars was weighed and germinated to determine numbers of pure live seed (PLS) m,2 before yield evaluation at four locations. Seed from ten cultivars was planted at 0ˇ7 and 2ˇ0 cm depth in a greenhouse study to evaluate relative seedling vigour. Cultivar mean single-seed weight ranged from 2ˇ4 to 4ˇ8 mg in 1997, 1ˇ8 to 4ˇ5 mg in 1998, and 2ˇ6 to 4ˇ6 mg in 1999. Seed germination ranged from 78ˇ8% to 98ˇ0% in 1997, 82ˇ3 to 98ˇ3% in 1998 and 77ˇ8 to 98ˇ3% in 1999. Seed number, PLS m,2, ranged from 675 to 1289 in 1997, 710 to 1550 in 1998, and 717 to 1179 in 1999. Among the ten cultivars evaluated for seedling vigour, seedling weight differed between planting depths and a significant cultivar by year interaction was observed. Seedling weight was highly correlated with seed weight at each seeding depth. The effect of increasing number of PLS m,2 on subsequent yield performance, although small, was consistently negative. These results indicate that target plant populations may be obtained more economically by adjusting seeding rates for seed size differences among cultivars and seed lots of annual ryegrass. [source] Fruit size and picking scar size in some blueberry commercial cultivars and hybrid plants grown in SW SpainINTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 7 2007Raquel Parra Summary Within a blueberry research program in SW Spain, five rabbiteye (Vaccinium ashei Reade) and nine southern highbush (Vaccinium corymbosum L.) commercial cultivars along with 38 hybrid plants, produced by crossing highbush and rabbiteye cultivars, were used. The differences in the fruit size and the picking scar size among the plants, and the annual differences within each plant were studied. No significant differences were found in the fruit length, width, weight and the picking scar size between the rabbiteye and the southern highbush cultivars, and neither between the cultivars and the hybrid progeny. However, significant differences were found among the cultivars and among the hybrid plants. The picking scar size correlates better with fruit width and weight than with fruit length, although correlation values are not high. Thus, outliers were observed, some of them interesting to be selected for having large fruits and narrow scars. The ratio between the picking scar and fruit width shows significant differences among subsequent years in many hybrid plants. [source] Progress in Wheat Resistance to Spot Blotch in BangladeshJOURNAL OF PHYTOPATHOLOGY, Issue 1 2006A. B. Siddique Abstract Spot blotch, caused by Cochliobolus sativus, is considered one of the most destructive diseases of wheat (Triticum aestivum) in the warm areas of South Asia. Over the past 20 years, wheat breeding efforts in the region have improved spot blotch resistance in susceptible commercial cultivars. This study assessed resistance and spot blotch-induced yield losses in newly released wheat cultivars developed in Bangladesh since the release of the landmark wheat variety ,Kanchan'. Replicated field studies were conducted during the 2003 and 2004 wheat seasons at two sites: a farmer's field and a research station in a warm region of Bangladesh where spot blotch has been a serious problem. Spot blotch affected 60% of the crop and caused yield losses of from 2% to 22%. Disease severity and disease-induced grain yield reductions were less in wheat genotypes developed since 1983, with a corresponding trend towards higher yield in newly developed varieties. The level of resistance to spot blotch in the new cultivars and advanced breeding lines represents considerable progress in breeding for resistance over the past two decades. [source] Can improvement in photosynthesis increase crop yields?PLANT CELL & ENVIRONMENT, Issue 3 2006STEPHEN P. LONG ABSTRACT The yield potential (Yp) of a grain crop is the seed mass per unit ground area obtained under optimum growing conditions without weeds, pests and diseases. It is determined by the product of the available light energy and by the genetically determined properties: efficiency of light capture (,i), the efficiency of conversion of the intercepted light into biomass (,c) and the proportion of biomass partitioned into grain (,). Plant breeding brings , and ,i close to their theoretical maxima, leaving ,c, primarily determined by photosynthesis, as the only remaining major prospect for improving Yp. Leaf photosynthetic rate, however, is poorly correlated with yield when different genotypes of a crop species are compared. This led to the viewpoint that improvement of leaf photosynthesis has little value for improving Yp. By contrast, the many recent experiments that compare the growth of a genotype in current and future projected elevated [CO2] environments show that increase in leaf photosynthesis is closely associated with similar increases in yield. Are there opportunities to achieve similar increases by genetic manipulation? Six potential routes of increasing ,c by improving photosynthetic efficiency were explored, ranging from altered canopy architecture to improved regeneration of the acceptor molecule for CO2. Collectively, these changes could improve ,c and, therefore, Yp by c. 50%. Because some changes could be achieved by transgenic technology, the time of the development of commercial cultivars could be considerably less than by conventional breeding and potentially, within 10,15 years. [source] Differential seedling resistance to the eyespot pathogens, Oculimacula yallundae and Oculimacula acuformis, conferred by Pch2 in wheat and among accessions of Triticum monococcumPLANT PATHOLOGY, Issue 5 2010C. Burt Eyespot is an economically important stem-base disease of wheat caused by two fungal species: Oculimacula yallundae and Oculimacula acuformis. This study investigated the efficacy of two sources of resistance, viz. the genes Pch1, introgressed into hexaploid wheat from Aegilops ventricosa, and Pch2, identified in wheat cv. Cappelle Desprez, against O. yallundae and O. acuformis separately. In a series of seedling bioassays Pch1 was found to be highly effective against both species. Although Pch2 was found to confer resistance against both pathogen species, it was significantly less effective against penetration from O. yallundae than O. acuformis. Furthermore, a quantitative trait locus (QTL) analysis was not able to locate any resistance to O. yallundae on chromosome 7A of Cappelle Desprez. This has important implications for the use of Pch2 in commercial cultivars as it is necessary to have genes that confer resistance to both pathogens for effective eyespot control. In addition, a set of 22 T. monococcum accessions was screened for resistance to both O. yallundae and O. acuformis to identify potentially novel resistances and to assess the accessions for evidence of differential resistance to the eyespot species. Significant differences in resistance to the two pathogens were identified in four of these lines, providing evidence for differential resistance in T. monococcum. This study demonstrates that future screening for novel sources of eyespot resistance should investigate both pathogen species. [source] Ovary colonization by Claviceps africana is related to ergot resistance in male-sterile sorghum linesPLANT PATHOLOGY, Issue 5 2003B. Komolong Ergot, caused by Claviceps africana, has emerged as a serious threat to sorghum hybrid seed production worldwide. In the absence of gene-for-gene-based qualitative resistance in commercial cultivars, varieties with high pollen production that can escape ergot infection are preferred. Recent demonstration of differences in ergot susceptibility among male-sterile lines has indicated the presence of partial resistance. Using chitin-specific fluorescin-isothiocyanate-conjugated wheat germ agglutin and callose-specific aniline blue, this study investigated the process of sorghum ovary colonization by C. africana. Conidia germinated within 24 h after inoculation (a.i.); the pathogen was established in the ovary by 79 h a.i., and at least half of the ovary was converted into sphacelial tissue by 120 h a.i. Changes in fungal cell wall chitin content and strategic callose deposition in the host tissue were associated with penetration and invasion of the ovary. The rate of ovary colonization differed in three male-sterile lines that also differed in ergot susceptibility. This work demonstrates a possible histological basis for partial resistance in male-sterile sorghum lines that could lay the foundation for variety improvement through further breeding and selection. 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