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- Author or Editor: P. Spiegel-Roy x
- Journal of the American Society for Horticultural Science x
Abstract
Staminate clone Israel 502 and ‘Kerman’ and ‘Lassen’ pistachio (Pistacia vera L.) on two rootstocks showed remarkable drought resistance under runoff farming in the Negev desert highlands. During favorable seasons, root distribution was fairly uniform down to 240 cm. Moisture depletion fluctuated between 58 and 477 mm during 1971-1974 because of great differences in flood water availability and scant annual rainfall (54–163 mm). Soil moisture was depleted in all strata well below the wilting point throughout the growing season in 1973 and from mid-July in 1974. Shoot growth terminated within 4–5 weeks. Although trunk growth continued at an even rate until August 1–15, the relative increment was 4.2–7% higher with the staminate clone. Extreme drought from the autumn of 1972 through 1973 (58 mm water depletion) did not prevent bud differentiation and high yields per tree (12.0 kg for ‘Kerman’, 9.5 kg for ‘Lassen’) in 1974.
Abstract
Soil moisture use, shoot growth, fruit size, and yield of apricot (Prunus armeniaca) trees (cv. Hatif de Colomer) were measured under flood water-spreading conditions in the desert. Root distribution was estimated from interpretation of soil moisture data. A highly significant correlation was found between pooled values of past and current seasons' water depletion values and current season's yield. Relative maximum water depletion (on a daily use basis) occurred during fruit maturation. Maximum trunk growth occurred in spring. In some seasons a second, small peak occurred in the autumn.
Shoot growth usually terminated by the beginning of June, and maximum trunk rate growth was usually (except in 1967) attained shortly thereafter.
Trees survived the extremely dry 1968 season (no flood, and only 80 mm of rain), with partial recovery in shoot growth and yield and full recovery in trunk growth during the subsequent year.
Moisture depletion under the trees, per 1000 m2, during the active period of the trees (March to end of September) was only 26 mm in 1968, about 100 mm in 1966, 106 mm in 1967 and 146 mm in 1969. Yields per tree (26 trees per 1000 m2) ranged from 1.4 kg (in 1970) to 27.4 kg (in 1967).
The central cylinder around the tree (2 meters in diam) accounted for the highest relative use of water in comparison with other annuli extending around the tree.
Excluding seeded offspring at an early stage could be of great value to the breeder concerned with the development of seedless grapes (Vitis vinifera L.). We used the random amplified polymorphic DNA (RAPD) technique to identify molecular genetic markers, analyzing 82 individuals of a progeny resulting from a cross between `Early Muscat' (seeded) and `Flame Seedless'. Seven variables representing the traits of seedlessness were analyzed: mean fresh weight of one seed, total fresh weight of seeds per berry, perception of seed content, seed size categories evaluated visually, degree of hardness of the seed coat, degree of development of the endosperm, and degree of development of the embryo. Among 160 10mer primers, 110 gave distinct band patterns. Twelve markers yielded significant correlations with several subtraits of seedlessness, mainly with the mean fresh weight of one seed and the total fresh weight of seeds per berry. Multiple linear regression analysis resulted in high coefficients, such as R = 0.779 for fresh weight of seeds per berry, when the seven markers were included as independent variables in the model. Most of the seeded individuals, about 44% of the progeny, could be excluded using a two-step process of marker assisted selection.
Abstract
Normal embryos and seedling plants were obtained from abortive ovules and seeds of seedless grape cultivars ‘Perlette’, ‘Flame Seedless’ and ‘Sultanina’. Plant development was accompanied by callus formation only in ‘Perlette’. The best medium was Nitsch’s with the addition of 10-5 m IAA and 10-6 m GA3. Excision and culturing of ‘Flame Seedless’ ovules 49 days after anthesis gave higher germination percentages and more viable plants than excision and culturing at anthesis plus 28. Selfed ‘Perlette’ and ‘Perlette’ × ‘Flame Seedless’ ovules cultured at 52 days gave 11%, and the reciprocal cross over 16% well developed seedlings. The significance of the findings for breeding stenospermocarpic grapes is discussed.