In crosses between stringless and stringy podded pea cultivars, all plants of the F1 and backcross to the stringy parent had stringy pods. F2 ratios varied widely among crosses, and populations always had more stringy plants than expected, based on a single locus. The ratio of nonsegregating (stringy): segregating F3 families derived from stringy F2 plants fit a single-gene hypothesis in half of the crosses. Backcrosses of F1 to the stringless parent fit the expected 1:1 ratio when the pollen parent was stringless, but the reciprocal backcrosses showed a deficiency of stringless plants, suggesting that poor competitive ability of pollen bearing the stringless factor was the reason for deficiencies of stringless plants. It is concluded that stringlessness is controlled by a single recessive gene for which the designation sin-2 is proposed. A reduction in pod size, plant height, and number of wrinkled seed segregates was associated with stringlessness.
The inheritance of a tendency to set parthenocarpic fruit in tomato (Lycopersicon esculentum Mill.) line Oregon T5-4 (T5) was studied in the field in crosses with 3 normal, seeded cultivars. F1, F2, and backcross data indicated that the parthenocarpic tendency in T5 is recessive. F2 data fit a 9 seeded : 7 seedless ratio, indicating that normal seediness requires 2 complimentary dominant genes. Parthenocarpic plants were earlier than seeded plants. Early ripening in T5 crosses resulted in most instances from a reduced period of time from first flower to first ripe fruit, and not from early flowering. The F2 from a cross of T5 with ‘Severianin’, an unrelated parthenocarpic cultivar, approached a theoretical 27 seeded : 37 seedless for 3 complimentary gene pairs and demonstrated that parthenocarpic tendency is determined by different factors in these 2 parents.
Fifteen broccoli (Brassica oleraceae L. Italica Group) breeding lines, OSU 101–OSU 115, have been released for use by commercial breeders. Favorable combining ability has been shown by various experimental hybrid combinations among these lines and between these lines and clubroot resistant Oregon State Univ. (OSU) lines released concurrently and described separately (2). This group of lines includes a range of characteristics which should be useful for breeding or direct use in F1 hybrids, including upright growth habit with good head exsertion for efficient harvest, excellent blue-green color, deeply branched heads, desirable bud type, earliness, and some resistance to downy mildew.
Broccoli (Brassica oleracea L. Italica Group) breeding lines OSU CR-2 to OSU CR-8 were selected and tested for clubroot (Plasmodiophora brassicae Wor.) resistance in the field at Corvallis and Tillamook, Oregon. All of the lines have shown resistance to downy mildew [Peronospora parasitica (Fr.) Tul.] in the field at Corvallis, and most have useful horticultural characteristics and are potentially useful as parents for F1 hybrids.
‘Gold Nugget’ is a determinate, fruitful tomato (Lycopersicon esculentum Mill.) cultivar, bearing golden colored cherry-type tomatoes, resembling ‘Yellow Plum’ in flavor. It was developed for home gardeners in western Oregon under cool summer conditions where it is early maturing and has a strong tendency for seedless fruit.
Oregon T5-4 is a tomato breeding line with a strong tendency for early parthenocarpic fruit set under cool conditions. Extreme earliness in T5-4 is associated with early flowering, the ability to set seedless fruit under low temperature, and possibly with fast ripening of seedless fruit. Although the line lacks uniformity and crack resistance, and has poor color, it has good flavor and could be used in home gardens in areas with a climate similar to that of western Oregon. The principal value of T5-4, however, should be in breeding small to medium-sized tomatoes for cool northern and coastal areas.
‘Oregon Cherry’ is a highly determinate, compact, fruitful, and early maturing cultivar. Developed in the Willamette Valley of Western Oregon, it should be adapted to cool summer areas where most cherry tomato culti-vars are late to mature. Similar to the F1 hybrid ‘Small Fry’ in fruit size and quality, ‘Oregon Cherry’ is less vegetative and vigorous, but more concentrated in fruit set, and generally earlier in production pattern. This cultivar should be useful in home gardens and for early fresh market production. It should be superior to most existing cultivars where a compact plant and earliness are needed.
An abnormal pod condition, in which bean pods are twisted, sometimes as much as 360°, was discovered in a selection of OSU 5256, a Bush Lake breeding line. The amount of twisting of affected pods and the number of affected pods/plant are both variable. F2 progenies from crosses between twisted pod line 5256-1 and two normal bush Blue Lake cultivars segregate 3 normal:1 twisted, showing that the twisted mutant is controlled by a single recessive gene.
'Oregon Spring' and 'Santiam' are early maturing, Verticillium wilt-resistant tomatoes with compact growth habit and medium-large fruit that are mostly seedless. The cultivars differ in fruit size and maturity. 'Oregon Spring' bears fruits that are larger than those of 'Santiam', but ripen about 5 days later. They should be especially useful in cool-summer areas where seedlessness and relative earliness will be maximized. 'Oregon Spring' and 'Santiam' will be most useful for home garden, roadside stand, and limited local market, since they lack the fruit firmness required for commercial handling.