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- Author or Editor: Randolph G. Gardner x
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Abstract
A mutant of the tomato (Lycopersicon esculentum Mill. cv. Flora-Dade) was characterized by straight pedicels oriented in an upright position. A genetic study indicated the mutant character was controlled by a single recessive gene, which has been tentatively designated as up-right pedicel (up). The up locus is linked to the jointless pedicel (j-2) character of ‘Flora-Dade’, with a crossover distance of 8.5 units.
Abstract
NC50-7, ‘Cherokee’ and ‘Mountain Pride’ are mid-season, determinate (sp gene) tomatoes (Lycopersicon esculentum Mill.) developed at the Mountain Horticultural Crops Research Station, Fletcher, N.C. ‘Cherokee’ and ‘Mountain Pride’ are adapted to vine-ripe harvest for local market and shipping. NC507 is useful as a parent in breeding for firmness and crack resistance and, in addition, is the male parent of the F1 hybrid ‘Mountain Pride’.
Abstract
Early blight, incited by Alternaria solani (Ellis and Martin) Jones and Grout, is a severe foliar disease of tomatoes in western North Carolina. Resistance breeding, initiated in 1976 at the Mountain Horticultural Crops Research and Extension Center, Fletcher, N.C. has resulted in the development of NC EBR-1 and NC EBR-2. Both lines exhibit a moderate level of foliar resistance to early blight.
Eight staked, determinate tomato (Lycopersicon esculentum Mill.) cultivars were harvested when green (before breaker stage) or when pink (breaker stage and riper) in two replicated field studies. In general, total yield and average fruit size were reduced when fruit were harvested at the green stage. Harvest maturity had only a small effect on occurrence of most fruit defects, except fruit cracking, which was more severe for pink than for green fruit in the early season experiment. Although total yields for pink harvested fruit were higher than for green harvested fruit in the early season study, the high incidence of fruit crack in pink fruit resulted in similar yields of U.S. combination grade (U.S. no. 1 and U.S. no. 2) fruit for both treatments. Because the largest fruit often bring a premium price, harvesting fruit when pink probably will result in a higher price per kilogram than harvesting fruit when green. Fruit harvested green, however, are generally firmer, more crack resistant, and require fewer harvests than fruit harvested pink.
There is a good market for heirloom tomatoes that, according to many consumers, taste better than regular tomatoes. Unfortunately, most heirloom tomatoes have little disease resistance, tend to crack, are rough in appearance, and are not uniform in size. Randy Gardner recently developed several new indeterminate hybrid tomatoes with the goal of combining the flavor of heirloom tomatoes with the disease resistance, uniform size, and good shipping characteristics of more modern varieties. Two tests, using organic and conventional practices, were conducted in Waynesville, N.C., in which three popular heirloom varieties (German Johnson, Mr. Stripey, and Cherokee Purple) and four late blight resistant hybrids (NC 0455, NC 0571, NC 0576, and NC 05114), replicated four times, were grown using a high trellis system. The highest yields were obtained with German Johnson NC 0455, and NC 0576 in the conventional trial and German Johnson NC 0455, and NC 0571 in the organic trial. Public taste test results revealed that the experimental hybrid cluster type, NC 05114, was ranked by over 82% of the participants as good or excellent. NC 0455 was rated as good or excellent by >83% of the participants, which was better than the popular heirlooms Cherokee Purple and Mr. Stripey. This study demonstrated that the heirloom-type hybrid tomatoes could be successfully grown in organic and conventional systems in Western North Carolina and that two out of the four tested had flavor ratings similar to, or better than, the three heirloom varieties tested.
Experiments were conducted in 1989 to determine the heritability of shortened fruit maturation (SFM) period in 871213-1, an inbred cherry tomato line (Lycopersicon esculentum var. cerasiforme (Dunal.) A. Gray), and to determine the relationship between this trait and fruit size. In the first study, a cross was made between 871213-1 and NC 21C-1, an inbred cherry line. NC 21C-1 had a mean maturation period of 40.8 days compared to 32.0 days for 871213-1. A mean maturation period for the F1 hybrid of 32.9 days and 32.2 days was found using 871213-1 as the female and male parent, respectively. Analysis of the data from parental, F1, F2 and backcross generations yielded estimates of broad-sense and narrow-sense heritabilities for SFM as 0.72 and 0.56, respectively. Further analysis indicated that genetic control of SFM was quantitative in nature and highly dominant. A test for epistatic interaction showed significance. In the second study, an F2 population from the cross 871213-1 x NC 309-1, a large-fruited tomato line (Lycopersicon esculentum Mill.), was evaluated to determine if any correlations existed between fruit size and SFM. Two fruit characteristics, locule number and fruit weight, were used as estimates of fruit size. Correlations between SFM and these two characteristics were +0.28 and +0.61, respectively. Broad-sense heritability of SFM was estimated as 0.64.