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  • Author or Editor: F.A. Bliss x
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Abstract

Three populations of near-homozygous inbred backcross lines of common bean (Phaseolus vulgaris L.) were produced using ‘Sanilac’ as the recurrent parent and 3 donor parents, ‘BBL 240’, 15R-148, and ‘Swedish Brown’. The method for producing inbred backcross lines included 2 successive backcrosses to the recurrent parent followed by 3 or 4 generations of self-fertilization using single seed descent. There was no conscious selection during the backcrossing or selfing stages. Lines were grown in the Held and analyzed for seed protein content, percentage of protein, seed yield, and seed size. In each population, the frequency of lines recovered having enhanced levels of phaseolin (compared to ‘Sanilac’) suggested that one or a few major genes (effective factors) for phaseolin had been contributed by the donor parent. In population 2, derived from ‘Sanilac’ crossed to ‘BBL 240’, there was evidence for possible linkage between enhanced phaseolin and the gene(s) controlling the electrophoretic banding pattern of the phaseolin polypeptide subunits. The nonprotein portion of the seeds of these lines was also less than that of the recurrent parent, resulting in generally smaller seeds. In contrast, some families in population 6 (donor 15R-148) having enhanced phaseolin also showed increased levels of the nonprotein constituents of the seed. Population 8 (donor ‘Swedish Brown’) was unique since lines with enhanced levels of phaseolin were recovered although the donor parent had a low phaseolin concentration (phaseolin/100 g flour) but large seeds with a high concentration of the nonprotein fraction. These results show that breeding lines with increased levels of phaseolin seed protein can be produced either directly by increasing the phaseolin concentration or indirectly by decreasing the nonprotein fraction of seed.

Open Access

Abstract

Four populations of inbred backcross lines of common bean (Phaseolus vulgaris L.), developed from crosses between ‘Sanilac’, the recurrent parent, and 4 donor parents (‘BBL 240’, 15R-148, ‘Swedish Brown’, and PI 229815), were analyzed for total seed protein percentage. In each population a substantial number of lines having significantly higher protein levels than ‘Sanilac’ were recovered. The basis for enhanced protein percentage was attributed to increased amounts (g/seed) of phaseolin and nonphaseolin protein, either singularly or together, and either with or without a decrease in the nonprotein seed fraction. Lines from different populations were characterized by different combinations of altered levels of the various seed fractions. Although seed size varied depending on the seed fractions present, no obviously shriveled seeds were observed. Lines having enhanced protein and seed yields comparable to or greater than the recurrent parent, ‘Sanilac’ were recovered.

Open Access

Abstract

Recurrent mass selection based on a desired gain index was employed to increase simultaneously seed yield and seed protein percentage in the common bean. Seed protein was increased from 21.9 to 24.6% after 2 cycles of selection. Mean seed yields of selected populations were not significantly greater than the mean of the unselected parents, but high yielding individual families were identified. Of particular interest was the family 2-4-1, with seed yields equal to the highest-yielding parent, and seed protein percentage higher than all parental lines in both years in which the experiments were conducted. Modifications in the selection procedure were proposed which should increase the efficiency of selection for seed yield.

Open Access

The discovery of bruchid resistance in wild beans and the demonstration that theArcelin protein is responsible for the resistance, provide an opportunity to develop resistant cultivars of common bean, Phaseolus vulgaris L. Arcelin expression is controlled by multiple alleles, which impart different levels of insect resistance. In field tests in Honduras and Brazil, backcross-derived lines with the Arl-1 allele were most resistant, especially to Mexican bean weevil. Seed mixtures of 0.80 Arl-1:0.20 susceptible and equal amounts of Arl-1,Arl-2, and Arl-3, and Arl-4 containing seeds showed resistanc elevels and seed yields similar to lines homogeneous for Arl-1. Breeding lines uniform for appearance and agronomic performance, but heterogenous for resistance genes are being tested as potential new dry bean cultivars having stable insect resistance.

Free access

Abstract

Genic male steriles of common bean (Phaseolus vulgaris L.) showed an average of 68% outcrossing. Outcrossing estimates are conservative due to selfing or sibbing made possible by unexpected fertility restoration in plants initially classified as male sterile. In growth chamber studies, a temperature regime of 30° day/18°C night for 2 weeks after flowering altered the expression of unstable sterile plants from partial sterile to male sterile. The reverse shift was conditioned by an 18° day/7° night temperature regime. Sterility was restored again by returning plants to the higher temperatures. The sterile F1 progenies of the cross male sterile x Swedish Brown-10 were all unstable. Temperature-stable steriles were obtained by selfing cold-treated, unstable steriles or by using these plants to pollinate stable steriles.

Open Access

Abstract

A procedure using nutrient culture media was developed to screen bean seedlings on an individual plant basis for reaction to Fusarium solani (Mart.) Appel & Wr. f. sp. phaseoli (Burk.) Snyd. & Hans. From over 800 accessions, 18 plant introductions and several cultivars of Phaseolus vulgaris were found to be either resistant or tolerant. Susceptible plants, grown with ammonium nitrate as the nitrogen source (210 ppm N) showed reduced symptoms compared to plants grown on nitrate-N only. Ammonium as the sole nitrogen source was toxic to bean seedlings at identical nitrogen concentrations. Results based on the nutrient culture technique were generally consistent with field reactions.

Open Access

Abstract

Ozone sensitivity was compared in F1 and F2 populations from crosses between 2 ozone-sensitive bean cultivars, ‘Spurt’ and ‘Blue Lake Stringless’, and 2 ozone-resistant cultivars, ‘Black Turtle Soup’ and ‘French’s Horticultural’, under controlled environmental conditions. F1 plants were as sensitive as the sensitive parent. About 10% of the F2 progeny obtained by selfing F1 plants appeared to be as resistant as the resistant parent and 90% of the progeny could be divided equally between a group as sensitive as the sensitive parent and a group intermediate in sensitivity between the parent plants. However, precise separation of F2 progeny was not possible because of the variability in injury expression. The average injury on the F2 plants was greater than the parental midpoint value and the variance in injury on the F2 plants was about 3.5x greater than that for the parents. The heritability of resistance to ozone was estimated to be 0.83. It was concluded that ozone resistance is recessive in P. vulgaris and appears to be regulated by a few major genes.

Open Access

Abstract

The inbred backcross line method was used to analyze the inheritance of fruit length and weight in cucumber (Cucumis sativus L.). Two populations were produced by crossing a small-fruited, adapted breeding line as the recurrent parent with 2 unadapted and large-fruited lines as donor parents. Marker genes were used in both populations to test for Mendelian expectations. Segregation was normal for all markers in both populations. Nevertheless, significant deviations from binomial expectations occurred, indicating that there were difficulties in estimating gene number and genetic variance without bias. Heritability was moderately high for fruit length and intermediate for fruit weight in both populations. No major genes controlling fruit length or weight were detected using the inbred backcross line method, and only estimates of minimum gene number were obtained. Inbred backcross lines having fruit weight equal to or greater than the large-fruited donor parent were recovered in both populations. However, in neither population were lines recovered with fruit as long as those of the donor parent.

Open Access

Abstract

Selected inbred backcross lines from 2 cucumber (Cucumis sativus L.) populations were studied to determine whether genetic variation existed within and between 2 populations for fruit length and weight. F1 hybrids from intra-population diallel and inter-population North Carolina Design II matings were evaluated in 1981 under greenhouse or field conditions. Significant genetic variability was found among selected inbred backcross lines within each population for fruit length and weight. General (GCA) and specific (SCA) combining ability estimates were significant, indicating that both additive and nonadditive effects were important for trait expression among lines from the same population. Analysis of inter-population design II F1 hybrids indicated that male and female (GCA) or additive effects accounted for most of the variation between lines for fruit length and weight. Significance of specific combinations (SCA) and the F2 data confirmed that genetic variation existed between populations. Therefore, selection and intercrossing of specific inbred backcross lines from both populations may lead to maximum fruit size and recovery of the desired horticultural characterisics of the recurrent parent. The inbred backcross line method is well suited for the transfer of genes controlling a quantitative trait from an unadapted or exotic source into a commercially acceptable type.

Open Access

Crown gall is an important disease of many fruit and nut crops, but little is known about sources of resistance. We screened germplasm from Prunus armeniaca L., P. angustifolia Marsh., P. argentia L., P. avium L., P. besseyi Bailey, P. bokhariensis Schneid., P. brigantica L., P. cerasifera Ehrh., P. cerasus L., P. dulcis (Mill.) D.A. Webb, P. fruiticosa Pall., P. hortulana Bailey, P. insititia L., P. japonica Thunb., P. mahaleb L., P. persica (L.) Batsch, P. serotina Ehrh., P. simonii Carr., P. sogdiana L., and P. webbii (Spach) Vieh. When either main stems or lateral branches of seedlings were inoculated with strains K12 and C58 of Agrobacterium tumefaciens (Smith and Townsend) Conn., the incidence of resistance was less than 10% except in some accessions of P. mahaleb L. where up to 30% of the plants were resistant. Some resistant plants were identified in other species, with P. insititia L. being the most promising. Symptoms based on presence and size of galls should be allowed to develop for up to 90 days after inoculation to reduce the likelihood of misclassifying plants as resistant when they are slightly susceptible.

Free access