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Abstract

A study was conducted to investigate the extent of genetic variations and the interrelationships of several quality traits of cultivars of navy and pinto bean (Phaseolus vulgaris L.) grown at 3 locations in Michigan. The measured traits were seed weight, initial weight of solids, surface color of dry and processed beans (L, aL, bL), weight of soaked beans, hydration ratio, clumps, splits, texture, washed and drained weight, and processed bean moisture. Significant cultivar differences were observed for most of the traits in both classes of beans. Location effects were highly significant for all traits. Certain traits showed significant cultivar × location interactions. Phenotypic correlation coefficients among pairs of characters indicated that, with few exceptions, there were low assocations among quality characters. Principal component analysis confirmed the independence of traits. A selection strategy based on a tandem selection procedure followed by construction of selection indices was suggested.

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In Dec. 1990, sweet cherry (Prunus avium L.) selections varied in floral bud kill from 9% to 92% following exposure to severe cold. In the following winter, the hardiness of two hardy and two tender selections was analyzed by differential thermal analysis (DTA) to screen selections for hardiness. In a mild winter, when buds remained at their minimum hardiness level, the hardy selections consistently were > 2C hardier than the tender selections. About one-half of that hardiness difference was associated with differences in tissue water content, the other half with unknown factors. Buds of the tender selections began to develop earlier and bloomed earlier than the hardy selections. DTA analysis of floral bud populations separated selections that clearly differed in floral bud hardiness.

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Abstract

H. L. de Vilmorin, in 1900, wrote “selection is the surest and most powerful instrument that man possesses for the modification of living organisms”. This early estimate of selection’s importance would probably be accurate today. While many techniques have since been developed as effective tools for the plant breeder-irradiation, colchicine, tissue cluture-his reward more frequently comes from selection pressure applied to population variation, natural or created.

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fluctuate depending on the development stage of shoots evaluated and on environmental conditions such as temperature and humidity. Selection using molecular markers that identify a genotype can be done accurately with low cost and time expenditure

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. Breeding line selection The 20 F 1 hybrid combinations from crosses involving the four snap bean breeding lines and five snap bean cultivars were generated in July 2008 ( Fig. 1 ). F 1 phenotypes were visually compared with phenotypes of the corresponding

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In 1987, `Starkspur Supreme Delicious' and `Melrose' were planted on eight apomitic apple selections made in Germany by Dr. Hanna Schmidt for use as rootstocks and compared to trees on M.7. Selection 2, was the most precocious, followed by trees on M.7, with selections 1 and 7 being less precocious than M.7. Selections 2 and 8 were 25% larger than M.7, while 1, 3, 4, and 7 were similar in size and 5 was 15% smaller than trees on M.7. Selections 2 and 8 had the highest cumulative yields/tree, followed by trees on M.7, with all other selections having lower yields. Internal bark necrosis (IBN) developed on the `Delicious' trees, with the most-severe symptoms on selections 1, 3, 4, 5, 6, and 7, with less-severe symptoms on 8 and very little present on trees on M.7. IBN was correlated with leaf Mn levels. In 1995, the highest density of flowering spurs occurred on M.7 and selections 3 and 7, with lower densities in selections 2 and 5. Selection 2 had the highest density of non-fl owering spurs, followed by selection 5, with all others having lower densities similar to trees on M.7.

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the result of a selection program, based on few morphological traits (see subsequently), aimed at identifying, throughout Sardinia, genotypes with good biomass and fruit production ( Mulas et al., 2002 ). The origin of each accession, the accession

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specificity, high sensitivity, and good reproducibility. Analyses of gene expression using qRT-PCR require stable reference genes as internal controls to normalize the data. The accuracy of the quantitative analysis is largely dependent on the selection of

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not produce seeds because of its strong self-incompatibility ( Kudo and Koga 1981 ), resulting in the absence of inbred lines. Many different genotypes of the F 1 offspring arise from crosses among cultivars/selections. A superior clone is selected

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-tolerant succulents [particularly stonecrop ( Sedum ) species] have been the dominant plant selections for extensive green roof applications ( Getter and Rowe, 2006 ). However, expanding the plant palette available for green roofs is desirable. Green roof vegetation

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