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Abstract
Aminoethoxyvinylglycine (AVG) at 50,100, and 200 ppm induced staminate flowers on 3 gynoecious cucumber lines in the greenhouse. Both the time of application and the type of water used to prepare the AVG solutions had a significant effect on the node at which conversion from pistillate to staminate first occurred and on the total number of nodes bearing staminate flowers. Plants treated with 100 and 200 ppm AVG were chlorotic for about 10 days after application.
Abstract
Silver nitrate at 100, 200 and 400 ppm and aminoethoxyvinylglycine (AVG) at 50, 100 and 200 ppm induced perfect flowers on gynoecious muskmelon (Cucumis melo L. cv. MSU-1G) in the greenhouse. Some phytotoxicity was observed in plants treated with AgNO3 and AVG at the higher concentrations.
Abstract
The muskmelon (Cucumis melo L.) breeding population Wisconsin (Wl) 998 was developed jointly by the U.S. Department of Agriculture, the University of Wisconsin, and Michigan State University to provide breeders and seedsmen with a source from which gynoecious inbreds can be developed for use in the production of hybrid cultivars. In addition to a high incidence of gynoecious plants, WI 998 provides other useful plant and fruit characteristics.
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.
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.