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  • Author or Editor: Donald H. Wallace x
  • Journal of the American Society for Horticultural Science x
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Abstract

One type of male sterility in carrots is expressed as the change of anthers to petaloid structures. Different shapes of petaloids were observed. According to the degree of petaloidy, they were filamentous, spoon-shaped, incomplete and complete. In most cases the 5 transformed stamens of a single flower exhibited the same shape, although in others some variability existed. Serial sections of normal and petaloid stamens revealed anticlinal cell division of the epidermal cell layer early in stamen primordia development to be associated with petaloidy. In one of the lots the anthers were not completely transformed and in this case there was an inverse relationship between the degree of petaloidy and anther locule development. In anthers where pollen grains dehisced, some were viable and germinable.

Open Access

Abstract

The inheritance of resistance to Fusarium solani f. phaseoli Kend. & Sny.) in Phaseolus vulgaris lines P. I. 203958 (N203), and 2114-12 which derives its resistance from P. coccineus, was studied under greenhouse and field conditions. It was concluded that: N203 and 2114-12 respectively possess 4 and 5-6 genes for resistance under the greenhouse-test conditions used; 4 of the 2114-12 genes for resistance are the same as the N203 genes; gene action is mostly additive but partial dominance of resistance appears in 9-13-week-old field-tested plants. Broad sense heritability was estimated as 62-64% under greenhouse conditions and as 22% and 79%, respectively, in 5 and 9-13-week-old field tested plants. The additive variance under greenhouse conditions was estimated as 72% and 40% respectively for resistance from 2114-12 and N203.

Open Access

Abstract

Resistance to T. basicola was found in Phaseolus vulgaris lines P.I.203958 (N203) and 2114-12. To determine the inheritance of resistance, these 2 lines were crossed with each other and with the susceptible cv. Redkote. Greenhouse tests were conducted on parental, F1, F2, and backcross progenies of each of the 3 crosses, and on F3 progenies of crosses ‘Redkote’ × 2114-12 and ‘Redkote’ × N203. The data indicate that N203 and 2114-12 possess the same genes for resistance, that resistance is partially recessive, and that resistance is controlled by approximately 3 genes. Broad sense heritability was estimated as 59% and the additive variance as 39%.

Open Access

Abstract

Previous reports suggest similarity between Fusarium and Thielaviopsis root rot resistances in beans (Phaseolus vulgaris L.), with regard to both source and nature of resistance. This study was conducted to determine the relationship between the genes controlling resistance to the 2 pathogens. The susceptible cultivar ‘Redkote’ was crossed with bean lines 2114-12 and P.I. 203958 (N203), both of which have resistance to Fusarium and Thielaviopsis. Four populations of F6 lines were separately developed. Two populations were derived from ‘Redkote’ × 2114-12; one was selected for resistance to Fusarium and the second for resistance to Thielaviopsis. Similarily, a Fusarium-resistant and also a Thielaviopsis-resistant population of F6 lines were derived from ‘Redkote’ × N203. Two additional populations of F4 plants, one resistant to Fusarium and one resistant to Thielaviopsis, were derived from the backcross [(‘Redkote’ × 2114-12, F2) × ‘Redkote’]. The F6 and F4 lines developed for resistance to Fusarium or to Thielaviopsis were subsequently tested for resistance to the other pathogen. The data indicate that genes controlling resistance to Fusarium and Thielaviopsis are different and non-linked.

Open Access