Pollen germination differed significantly between and within 3 interspecific hybrid populations and their parents. Pollen germination of populations of ‘Sharpblue’ (Vaccinium X sp.) × V. myrsinites Lamark (38%) and ‘Sharpblue’ × V. darrowi Camp (33%) was lower than mid-parent means of 45% and 37%, respectively. ‘Avonblue’ × V. myrsinites averaged higher in pollen germination than the mid-parent, 42% vs. 32%. Pollen germination of ‘Sharpblue’ × V. myrsinites hybrids varied most in pollen germination, ‘Avonblue’ × V. myrsinites hybrids least, and ‘Sharpblue’ × V. darrowi hybrids intermediate.
Eleven cultivars of Vaccinium ashei Reade in a 10-year-old planting were compared for number of flowers per inflorescence and for percentage of the flowers that set fruit on bagged and open-pollinated branches. Mean flower number per cluster ranged from 7.6 for ‘Bluegem’ to 5.3 for Florida-M. Mean percentage of fruit set on open-pollinated branches ranged from 75% for ‘Southland’ to 36% for ‘Tifblue’. On branches bagged to exclude bees, the range was from 21% for ‘Beckyblue’ to 3% for Tifblue.
One trait desired by consumers for table grapes (Vitis spp.) is seedlessness, which is caused by either embryo abortion (stenospermocarpy) or parthenocarpy (2). Inheritance of stenosperm ocarpy is poorly understood and still under investigation (4, 5, 7, 8). Breeders have developed seedless grapes by using stenospermocarpic parents as pollen sources (2, 7, 8). In vitro culture of stenospermocarpic ovules/embryos prior to abortion makes it possible to hybridize seedless females with seedless males, in hope of increasing the number of seedless progeny (1, 3, 6).
Seed from three octoploid (2n = 8x = 56) Fragaria species [F. × ananassa Duch., F. chiloensis (L.) Duch., and F. virginiana Duch.] and three diploid (2n = 2x = 14) species (F. vesca L., F. viridis Duch., and F. daltoniana J. Gay) were placed in vitro on water agar (WA) and ex vitro on 1 sand : 1 sphagnum (v/v) mix. Seed of the octoploid species germinated best regardless of medium. Octoploid species also exhibited better establishment on modified Boxus proliferation medium than the diploids. Five in vitro germination media were tested for F. vesca and F. × ananassa. Fragaria × ananassa germinated best when WA, or WA + sucrose (Su) + 0.1, or 0.05 strength Boxus proliferation nutrients (Nu) was used as the germination medium. Fragaria vesca showed no difference in germination on Su or Nu. However, establishment of F. vesca on proliferation medium was improved if Nu was included in the germination medium. Data indicated that selection for diploid genotypes with good in vitro establishment is possible.
‘Nesbitt’ is a black-fruited muscadine grape (Vitis rotundifolia Michx.) released by the North Carolina Agricultural Research Service. ‘Nesbitt’ is named in memory of the late Dr. William B. Nesbitt, who was instrumental in muscadine grape improvement.
Eleven suspected somatic mutations, consisting of 7 trees and 4 individual branches of the ‘Montmorency’ cherry, were compared with standard ‘Montmorency’ for phenotypic traits including tree height, trunk circumference, leaf area, crotch angle, resistance of flowers to frost injury, pollen germination, fruit set, individual fruit weight, fruit removal force, and yield. Differences occurred between some variants and ‘Montmorency’ controls for all characters except fruit removal force. All variants were tetraploid (2n = 32), as is standard ‘Montmorency’, with no evidence of cytochimerism.
The anthocyanin (Acy) content of 12 Euvitis × Vitis rotundifolia hybrids, 3 V. vinifera L., one V. × labruscana, and one V. rotundifolia Michx. clone were analyzed by high performance liquid chromatography (HPLC) techniques. All intersubgeneric hybrids contained mono- and diglucoside Acy, and all but one produced acylated Acy. A total of 40 pigments was separated, with ‘Concord’ having the most at 31. An additional unidentified pigment was detected in ‘Noble’. Sufficient variation was present in the hybrids for selection of genotypes that would improve color of wines. Relative Acy content (percentage of total) in the hybrids ranged from 2.3% to 44.3% for malvidins, 0.7% to 30.3% for petunidins, 0.8% to 69.2% for peonidins, 0.0% to 17.2% for cyanidins, and 0.5% to 52.3% for delphinidins. Relative content of acylated Acy forms in the hybrids ranged from 0.0% to 51.1%. Total Euvitis-type pigmentation (monoglucoside plus acylated Acy) in the hybrids ranged from 19.5% to 55.0%.
Fruit, stems, tendrils, leaves, and leaf petioles of4Noble’ muscadine grape (Vitis rotundifolia Michx.) were analyzed using high performance liquid chromatography (HPLC) techniques. All five of the known 3,5-diglucoside forms of delphinidin (Dp), cyanidin (Cy), petunidin (Pt), peonidin (Pn), and malvidin (Mv) present in fruit of muscadine grape were detected in all sampled tissues except leaves, which contained only Dp, Cy, and Pt in detectable quantities. A sixth unknown pigment was detected in the fruit, and Dp 3-monoglucoside was detected in the leaves. Correlations were calculated to explore pigment relationships between fruit and vegetative tissues. Use of tendrils was best for predicting fruit Cy (r = 0.60), Mv (r = 0.57), Pn (r = 0.66), and Pt (r = 0.87). Use of stem tissue was best for predicting fruit Dp (r = 0.66). Prediction equations are given, and prediction of Cy could be improved by using both tendril and leaf measurements in a multiple regression (r = 0.80).
Fruit, stem, tendril, leaf, and leaf petioles of 10 selections of muscadine grape (Vitis rotundifolia Michx.) were evaluated for pigment quantity and quality using high performance liquid chromatography (HPLC). All five of the 3,5-diglucoside pigments present in the fruit were present in detectable levels in the other four tissues of at least one selection except for leaves, which lacked peonidin (Pn) in all cases. Eight selections lacked detectable quantities of malvidin (Mv) in the leaves, one lacked Pn in stems, and six lacked Pn in leaf petioles. A sixth unknown pigment was detected in the fruit of two selections, and delphinidin (Dp) 3-monoglucoside was detected in leaves of all 10 selections. Fruit to vegetative tissue correlation and significance values were calculated across genotypes, with r ranging from 0 for fruit to leaf Mv to 0.53 for fruit to leaf petiole Dp. Stepwise regression analysis determined that leaf petiole and leaf tissue measurements together could predict fruit Dp better than could leaf petiole measurements alone (R = 0.80, significant at Ρ = 0.03; and R = 0.53, significant at Ρ = 0.11, respectively), and fruit petunidin (Pt) could be predicted from leaf petiole and stem measurements better than from leaf petiole measurements alone (R = 0.68, significant at Ρ = 0.12; and R = 0.40, significant at Ρ = 0.25, respectively).