Search Results
Abstract
A 6-parent diallel was used to investigate the relationship between blossom-end rot (BER) and the uniform-ripe fruiting trait of tomato (Lycopersicon esculentum Mill.). Three parents possessed the uniform-ripe character (uu), and 3 parents bore green-shouldered fruit (UU). Data were collected during 6 harvests for both BER incidence (%) and severity (lesion size). Significant differences existed among the F1 genotypes UU, Uu, and uu for BER incidence (P=5%) and severity (P=l%). BER incidence tended to increase as the u allele increased from 0 to 2.
Abstract
The relationships between photosynthetic rate, yield, and yield components of forcing tomatoes (Lycopersicon esculentum Mill., cvs. Tuckcross V and Tuckcross 533) under variable lighting and spacing were studied during the dark winter of 1972-73. Yield and its components were all highly and positively correlated with both cloudy-day (90-110 W/m2 light intensity) and sunny-day (200 W/m2 or higher) photosynthetic rates. The rate-yield relationship remained nearly constant irrespective of the predictor variable. Better linear response of yield and its components to cloudy than to sunny-day photosynthetic rate was observed. Photosynthetic rate accounted for more than 60% of the yield variation.
Abstract
Total glycoalkaloid (TGA) contents were determined in the mature green fruit of 7 lines representing 6 Lycopersicon species. Significant differences were found among all lines except the L. esculentum entries and among clusters within 6 lines. LA 1028 (L. chmielewskii Rick, Kesicki, Fobes & Holle) had the highest mean TGA content of 114 mg/100 g fresh weight; 31-St-34 (L. esculentum Mill.) had the lowest mean TGA content of 7 mg/100 g fresh weight.
Abstract
The practical significance of incorporating TMV resistance into F 1 hybrid tomatoes can hardly be over-estimated. Internal browning, graywall and blotchy ripening disorders continue to plague the greenhouse tomato grower and constitute perhaps his greatest current disease problem. Lewis and Taylor (6) pointed out the confusion which exists with regard to the association of TMV with these disorders.
Abstract
The use of MagAmp as a nutrient source in 6 low Ca media reduced blossom-end rot (BER) incidence in ‘Patio Hybrid’ tomato. When Osmocote alone supplied the nutrients, BER incidence was significantly higher than when MagAmp was the sole nutrient source. A combination of MagAmp and Osmocote significantly reduced BER incidence below that observed when Osmocote was the sole nutrient source. Indirect evidence that Mg may have substituted for Ca in maintaining normal metabolism of the fruit is presented.
Abstract
Calcium adsorption on the root exchange sites of 4 vegetables as determined by the isotopic exchange method (Ca40–Ca45) was a function of its concentration in the external solution surrounding the roots. As the Ca concentration was increased over the range 0.2 me–8.0 me Ca/1, there was an increase in the Ca adsorbed on roots of sweet corn, cv. ‘Gold Rush’, garden bean cv. ‘Topcrop’, lettuce cv. ‘Bibb’ and cabbage. The Ca adsorption curve of all 4 vegetables showed a plateau between concentrations of 1 and 2 me Ca/1. Root CEC values obtained at Ca concentrations corresponding to this plateau compare closely with values reported by other methods, and are more representative of established CEC values than those reported where the Ca concentration in the external solution was 0.5 me Ca/1.
Abstract
In a diallel study involving 5 unrelated tomato lines, the mean values of non-parental single crosses for fruit weight, soluble solids, and titratable acidity were found to predict with confidence the performance of double crosses. No significant correlation was obtained between the observed and predicted fruit pH values. The small magnitude of difference among the observed values involving the same lines in a series of double crosses and the small magnitude of variation among the single crosses made it difficult to establish the best order of combining the lines in a double cross.
Abstract
The variability, mode of inheritance, and gene action for soluble solids was studied in a cross of 2 divergent lines, Mo. Accession 223, a selection of PI 272689, and 1-417-1. About 3 gene pairs were indicated to control soluble solids. Additive gene action accounted for a heritability of about 35%. In the broad sense, heritability was about 59%, suggesting that non-additive genetic variance was about 25%. Evidence for dominance and for epistatic interactions of genes appeared to be lacking.
Abstract
The variability, mode of inheritance, and gene action for tomato fruit weight was studied in a cross of 2 divergent lines, Mo. Accession 223 (a selection of USD A P.I. 272689), and 1-417-1. The data indicated that more than 10 gene pairs, and possibly as many as 20, differentiated the parents for fruit weight in this cross. Partial dominance of small fruit weight genes was shown. No evidence of epistatic interaction was found. Gene action was largely geometrically cumulative. Heritability estimates in the broad sense was 29%. Little additive genetic variance was detected.
Abstract
The interrelationships between tomato fruit weight, Brix, pH and titratable acidity were studied in 2 constant parent groups of F1’s, their 11 parental lines and 2 sets of P-F1’s. Estimates of genetic and phenotypic correlations between high Brix and high titratable acidity and between low pH and high titratable acidity suggested considerable pleiotropic role of genes. The desirable assocation of high Brix with low pH was phenotypically unstable and appeared to have little detectable genetical basis. Fruit weight was poorly correlated with quality traits. Implications of these findings in a breeding program are discussed.