part by the Cornell University Vegetable Breeding Institute and USDA IFAFS Award No. 2001-52100-11347.
Development Center for cotton aphid resistant germplasm. This study was funded in part by the Cornell University Vegetable Breeding Institute, a consortium of companies that support plant breeding research at Cornell, along with funding from USDA IFAFS Award
Inheritance of a twisted pod characteristic, in which bean pods develop with a twist that sometimes exceeds 360°, was studied in crosses between round-podded green bean cultivars. In crosses between `Oregon 91G' (normal) or `Oregon 54' (normal) and OSU 5256-1 (twisted), the F1 was normal. Segregation in F2 populations, tested over a 4-year period and including 4,995 plants, clearly fit a 3 normal: 1 twisted ratio. All plants of backcrosses of the F, to the normal parent were normal and backcrosses of the F1 to the twisted parent segregated 1 normal: 1 twisted. The ratios observed indicated that twisted pods are conditioned by a single recessive gene for which the symbol tw is proposed.
‘Gallatin 50’, a bush cultivar not of ‘Blue Lake’ background, and ‘Oregon 1604’, a bush cultivar of ‘Blue Lake’ type, were crossed with distortion susceptible lines of ‘Blue Lake’ type. Environment affected distortion expression; the best expression was obtained in the greenhouse while expression was much reduced in the field. Ratios obtained suggested distortion is primarily controlled by a single dominant gene, designated Ld. ‘Oregon 1604’ carries the recessive allele for normal. ‘Gallatin 50’ carries a major dominant gene, designated Ds, that supresses the expression of the dominant gene Ld for leaf distortion tendency. Results also suggested that modifying factors are involved and are responsible for levels of susceptibility among parents and progenies. Additional crosses between susceptible lines showing severe to mild distortion indicated that these lines carried the same major genes for distortion, but differed in modifying factors.
The heritability of efficiency in phosphorus utilization under deficiency stress was investigated using 6 bean families derived from crosses between selected efficient, moderately inefficient, and inefficient lines. Total plant dry weight (DW) was used as an index of efficiency. Epistasis, notably additive by additive and dominance by dominance gene effects, made imyor contributions to the efficiency in P utilization. Additive and dominance gene effects also made significant contributions. Estimates of broad sense heritability for total plant DW showed that efficiency in P utilization was a highly heritable trait. Narrow sense heritability estimates for total plant DW were high in all families studied.
The winter survival of 10 pea cultivars of differing cold hardiness was studied under ground-level culture and on raised beds in moist semi-maritime conditions (CorvaUis, Oregon) and in more severe continental conditions (Weston, Oregon). There was survival in 7 cultivars at CorvaUis and 6 at Weston. Planting on raised beds at Corvallis significantly increased survival. This effect was consistent for all cultivars having appreciable survival rates. At Weston, the mean survival was higher on ground level plantings, but cultivars, responded differently to cultural systems. Of the 6 surviving cultivars, only the 2 least hardy had significantly higher survival on ground level plantings.
The Cornell University vegetable breeding program has developed cucumbers ( Cucumis sativus L.) resistant to a spectrum of diseases, including powdery mildew ( Cavatorta et al., 2012 ; Jahn et al., 2002 ) and viruses ( Munger, 1993 ). The program
economic and quality traits. Vegetable breeding has always been a balancing act in which breeders have tried to combine attributes like host plant resistance to disease with yield and vegetable quality, all at the same time. Most improvements made in the