An Integrated Approach of Breeding and Maintaining an Elite Cultivar of Snap Bean

Abstract

to compensate for the declining native variability by deliberate maintenance. This study is an attempt to describe a functional breeding andMajor breeding objectives in snap bean (Phaseolus maintaining program of intraselection in a traditional snap bean vulgaris L.) concern the development of cultivars com-(Phaseolus vulgaris L.) cultivar. The program was applied in three bining high productivity, stable yields, earliness, pest stages. The first thing examined was the existing genetic variability of source material for earliness and pod yield potential. Single-plant and disease resistance, tolerance to environmental frequency distributions with positive skewness for earliness showed stresses, and desirable agronomic-horticultural attrithat the frequency of unfavorable alleles was high. For total pod butes (Silbernagel, 1986; Singh, 1992). The achievement yield, distribution was found normal. Thus, the end-target should be of such objectives should take into account the cropping selection for early maturity, keeping, and stabilizing high yield. The systems, the ecological conditions, and the preference seed shape uniformity was added as third criterion of selection. Secof consumers in the target areas. In temperate areas ondly, combined pedigree intraselection, based on widely spaced sinof monocropping and intensive cultivation, mechanical gle-plant performance, for the prementioned traits was applied for cultivation, and industrial processing of the final product three successive generations. The evaluation of the third-generation have directed efforts to breed varieties with determinate families revealed progenies with high yield, earliness, and stability of bush type, short duration, concentrated pod maturation, performance. Thirdly, the end-product of the program applied was and uniformity in plant height, seed shape, and size. to restore or even improve the cultivar. The evaluation of improved selections of fourth-generation families and of the source material, Much of the genetic improvement of snap bean has at dense stand, showed that all families were the only ones producing been achieved through the selection of varieties by high and stable early fresh pod harvest, even 53 d after planting applying conventional breeding techniques of self-polli-(53.25-80 g/plant, compared with 0 g/plant of the control). The total nated crops (Singh, 1992) such as bulk, pedigree, backpod yield of all the families was 219 to 276% superior compared cross, and their modifications (Brim, 1966) such as the with source material. Conclusively, the widely spaced single-plant single seed descent method. Conventional pedigree secombined pedigree intraselection was proved reliable and effective lection based on visual evaluations may be difficult, in restoring or even improving the local cultivar of snap bean according especially for traits with low to moderate heritability to update demands.such as seed yield (Patino and Singh, 1989). Bulk breeding methods were effective for endowing genotypes with a better yield stability (Allard,...

Density effects on environmental variance and expected response to selection in maize (Zea mays L.)

“…Duvick (2005) claimed that the target of densityneutral hybrids is accomplishable and such hybrids would optimize the resource use efficiency, particularly under drought-prone conditions. The capacity of the honeycomb procedure to successfully select for productivity at the typical farming densities was validated by experimental reports in other crops as well, such as snap bean (Phaseolus vulgaris L.) (Traka-Mavrona et al 2000), tomato (Lycopersicon esculentum L.) (Christakis and Fasoulas 2002), in switchgrass (Panicum virgatum L.) (Missaoui et al 2005), in bread wheat (Tokatlidis et al 2006), in rice (Oryza sativa L.) (Ntanos and Roupakias 2001), and in cotton (Batzios et al 2001).…”

Development of crop cultivars by honeycomb breeding

“…Honeycomb intra-cultivar selection in wheat (Fasoula 1990;Tokatlidis et al , 2006, maize (Tokatlidis 2000), cotton (Fasoulas 2000;Tokatlidis et al 2008bTokatlidis et al , 2011 and soybean Boerma 2005, 2007) succeeded in upgrading cultivars for yield, stability and important agronomic traits related to product quality and tolerance to stresses. Other reports for successful honeycomb selection exist in cotton, lentil, maize, rice, snap bean and tomato (Traka-Mavrona et al 2000;Batzios et al 2001;Ntanos and Roupakias 2001;Tokatlidis et al 2001Tokatlidis et al , 2005Christakis and Fasoulas 2002;Vlachostergios et al 2011). Honeycomb breeding has led to the development and registration of 18 elite soybean germplasm lines with superior agronomic and seed traits (Fasoula et al 2007a, b, c).…”

Performance of Common Bean (Phaseolus vulgaris L.) Landraces from Spain in the Atlantic and Mediterranean Environments

“…The wide ranges of variation displayed by all the traits emphasize strongly the possibilities for selection within the landraces because many of them are actually mixture of lines. Bean mixtures of different types according to some characteristics such as seed colour and pattern are often seen in farmer fields and markets in many countries (Kaplan 1981, Traka-Mavrona et al 2000, Rodin˜o 2001, Piergiovanni et al (in press)). In the present research each landrace was evaluated according to its average value for each quantitative trait and the seed was described according to the most representative type in the mixtures.…”