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Abstract
Traditionally, plant breeders have been concerned with haracteristics such as yield and disease resistance which can be evaluated subjectively or by straightforward objective methods where differences are qualitative and maximum manifestation of the trait is desired. Quality has not been a principal objective in most plant breeding programs; frequently, it has been an afterthought. Once the other desired characteristics have been achieved, there is an attempt to select for adequate quality. The attention that quality characters have received varies greatly among the numerous quality traits. Color, for example, has received considerable attention because of its importance to appearance and consequently salability. In contrast, nutritional value and flavor have been mainly neglected by plant breeders.
Abstract
Inheritance of the viscosity potential of tomato (Lycopersicon esculentum Mill.) fruits was studied using parents and F1, BCP1, BCP2, and F2 progeny from the crosses VF145-7879 × VF109 and VF145-7879 × 9039-M. Differences in viscosity from both crosses were controlled by 3 or fewer genes. In the VF145-7879 × VF109 cross there was bimodal distribution of BCP1 and F2 progeny which supports relatively simple inheritance. Partition analysis of the VF145-7879 × 9039-M cross supported the view that 3 or fewer genes were involved in viscosity difference. The heritability estimates were high for both crosses (0.75 and 0.68) and analysis of genetic variance showed that additive genic effects were most important. In the VF145-7879 × VF109 cross there was small, but significant, additive × dominance interaction whereas in the VF145-7879 × 9039-M there was no interaction but there were dominance effects. Study of the heritabilities of 5 components of the alcohol-insoluble solids did not clarify the genetic analysis of viscosity potential. Possible effects of competition for photosynthate on the genetic analysis are discussed.
Abstract
The soluble solids content of ripe fruit of tomato (Lycopersicon esculeutum mill.) is positively associated with starch content early in fruit development. When 14C-sucrose or 14C-glucose were injected, the young fruits of the breeding line LA 1563 contained greater amounts of 14C in starch than those of the cultivars ‘UC 82B’. This, and the larger pool of hexoses in young fruits of ‘UC 82B’, implies that difference in starch synthesis is a primary factor affecting starch levels. The differences between 2 genotypes for fruit respiration and their ability to take up sucrose from an agar medium suggest that starch accumulation is a result of greater sink activity.
Abstract
White and brown accessions of tepary bean (Phaseolus acutifolius Gray var. latifolius) and navy bean (Phaseolus vulgaris L. ‘Fleetwood’) were germinated at 0.0, −0.5, −1.0, −1.5, −2.0, and −2.5 MPa of NaCl at 25 or 35C for 9 days. Differences in germination percentages and rates between the two species were significant, especially at the higher salt concentrations. At 25C and salinities greater than or equal to − 2.0 MPa, tepary accessions had significantly higher percentage germination and germination rates than navy. At 35C this difference was noted at −1.5 MPa. The fresh weights of root plus hypocotyl appeared lower than controls at even the lowest concentration of salinity (− 0.5 MPa), suggesting that seeds germinated with NaCl did not produce vigorous seedlings. Of the three beans tested, the two tepary beans were more tolerant to NaCl than the navy bean, with the white tepary being most tolerant.
Seeds of two tepary bean lines (Phaseolus acutifolius Gray var. latifolius) and one navy bean cultivar (P. vulgaris L. `Fleetwood') were tested with 0.0-, – 0.3-, –0.6-, -0.9-, -1.2-, or – 1.5-MPa NaCl solutions to determine their relative salt tolerance during germination and emergence. Developmental stage was not affected at – 0.3 MPa, but with salinities more negative than -0.9 MPa, `Fleetwood' developed more slowly than the tepary lines; no plants emerged at – 1.5 MPa. Teparies tended to maintain higher water and osmotic potentials than navy over the range of NaCl concentrations used, although turgor was similar for all three genotypes. Leaf area was reduced more in navy than in white tepary at – 0.6 and – 0.9 MPa. Dry weights of navy were higher than those of either tepary bean at all NaCl concentrations, although decreases at higher salinities relative to 0.0 MPa were greater for navy than for teparies. Root: shoot ratios were higher at – 0.3 MPa than at 0.0 MPa, but were lower at the higher NaCl concentrations for all three genotypes. Overall, tepary beans tolerated NaCl better than navy. The characteristic that best indicated differences in salt tolerance was developmental stage.
Abstract
The relationship of plant growth habit to establishment of a successful symbiosis between Phaseolus vulgaris L. and Rhizobium phaseoli was examined. A determinate and an indeterminate cultivar of bean were inoculated with a pure culture of R. phaseoli 127K44, and plant development was measured using the plastochron index. Time required to nodulate as determined by nodule count did not vary between plant types. The timing, duration, and overall success of the symbiosis as measured by increased acetylene reduction, dry weight, and transport of ureides and amino acids were related to the period of exponential leaf expansion in both the determinate and indeterminate cultivar.
The regulation of anther dehiscence by relative humidity (RH) was assessed for detached anthers and detached whole flowers from a limited selection of apricot (Prunus armeniaca L.), peach [P. persica (L.) Batsch], and almond [P. dulcis (Mill.) D.A. Webb, syn. P. amygdalus Batsch; P. communis (L.) Arcangeli, non Huds.] genotypes, as well as an almond X peach F2 progeny. Dehiscence was evaluated at 33, 64, 87, 93 and 97% RH for detached anthers, and at 33, 64 and 97% RH for whole detached flowers. Anther dehiscence was suppressed with increasing RH for all genotypes. Apricot anthers showed the greatest dehiscence at low RH and measurable dehiscence at high RH even when detached. Anther dehiscence in almond appeared more suppressed than in apricot at all RH levels tested, being completely suppressed by high RH in detached anthers. Peach genotypes exhibited the full range of variability between apricot and almond patterns. Evidence for transgressive segregation of RH-controlled anther dehiscence was observed in the occurrence of cleistogamy in an almond × peach F2 progeny. Rates of anther dehiscence were approximately linear with change in RH in detached anthers but exhibited a more buffered, step-wise response when detached whole flowers were tested. Results are consistent with field observations, and highlight the low but measurable risk of cleistogamy in these species, as well as opportunities to modify the breeding systems and crossing environments to facilitate controlled hybridization, and to reduce pollination vulnerability to adverse environments.
Clonal selection of European winegrapes (Vitis vinifera) allows the exploitation of an important source of genetic diversity. In the 1980s, many `Pinot noir' clones, previously unavailable in the U.S., were imported from France. To provide information on their performance under Oregon soil and climate conditions, 20 `Pinot noir' clones were established in a replicated trial in Alpine, Ore., planted in 1989. In this study, yield components, pruning weight, and juice composition of the 20 clones were measured for the 1995 through 1999 seasons. Skin anthocyanin concentration was measured for the 1996 through 1999 seasons. Clones included in the trial were Colmar (COL) 538, Dijon (DJN) 10/18, DJN 113, DJN 114, DJN 115, DJN 375, DJN 60, Espiguette (ESP) 236, ESP 374, Foundation Plant Services (FPS) 2A, FPS 4, FPS 10, FPS 16, FPS 17, FPS 22, FPS 23, FPS 29, FPS 31, FPS 32, and FPS 33. For all responses except juice pH and skin anthocyanin concentration, there were significant clone by year interactions. COL 538 had the highest 5-year mean yield (2.93 kg/vine); FPS 29 had the lowest (1.21 kg/vine). DJN 10/18, FPS 4, FPS 22, and FPS 31 were among the five highest-yielding clones. Other low-yielding clones included DJN 115, ESP 374, FPS 17, and FPS 23. Pruning weights were generally correlated with yields. COL 538 had the highest 5-year mean pruning weight (0.81 kg/vine) and FPS 17 had the lowest (0.48 kg/vine). Other clones with relatively high pruning weights were FPS 2A, FPS 4, and FPS 22. Other clones with low pruning weights were FPS 23 and FPS 29. FPS 22 and FPS 17 had the highest (1.13 g/berry) and lowest (0.93 g/berry) 5-year mean berry weights, respectively. Clones with 5-year mean cluster weights >100 g included DJN 10/18, ESP 236, and FPS 31. Those with cluster weights <80 g were DJN 115, FPS 17, and FPS 29. FPS 2A had the highest 5-year mean juice soluble solids concentration (SSC) at harvest (23.8%). FPS 10, FPS 29, DJN 113, and DJN 115 also had relatively high SSC. DJN 60 had the lowest 5-year mean SSC at harvest (22.0%). FPS 22, FPS 33, COL 538, and ESP 374 also had relatively low 5-year mean SSC at harvest. DJN 115 had the highest 5-year mean juice pH (3.15). DJN 113, FPS 29, and FPS 10 also had relatively high juice pH. FPS 22 had the lowest 5-year mean juice pH at harvest (2.97), and DJN 10/18, FPS 2A, and FPS 17 also had relatively low pH. Clones with higher SSC and pH generally had lower titratable acidity. FPS 2A had both high SSC and high titratable acidity. FPS 23 and FPS 17 had the highest skin anthocyanin concentration (2.10 and 2.07 mg·g-1 berry, respectively). The range of skin anthocyanin concentration among the other clones was relatively narrow (1.17-1.47 mg·g-1 berry). FPS 2A, FPS 4, and FPS 10 generally had above mean SSC and yield. FPS 29, DJN 113, DJN 114, and DJN 115 consistently had above mean SSC but below mean yield.
Abstract
This very complex topic must be dealt with only superficially here. Volumes have been written about sensory evaluation, and the best that this short paper can do is to generalize about sensory evaluation of horticultural commodities from our experience with tomatoes.