compatibility ( Blechert and Debener, 2005 ; Byrne and Crane, 2003 ; Cairns, 2000 ; Jian et al., 2010 ; Spiller et al., 2011 ; Ueckert et al., 2015 ; Zlesak, 2009 ), and a broad diversity of flower and plant growth habits. Zuzek et al. (1995) described
greater in density but more upright in growth habit compared with ‘Tifway’, the industry standard triploid (2n = 3x = 27) interspecific F 1 hybrid. If African bermudagrass plants could be identified with a more prostrate growth habit, it may be possible
recorded ( Fig. 1 ). Fig. 1. Nine growth habits of 1-year-old F 2 plants from an interspecific cross between Jatropha curcas and dwarf Jatropha integerrima observed in dry season 2011, ( A ) tall-spreading, ( B ) tall-upright, ( C ) tall-erect, ( D
Summer squash cultivars (Cucurbita pepo L.) of the Zucchini type were classified on a scale of 1 (open) to 5 (dense growth habit). A trial with 5 cultivars indicated that yield is not dependent on heavy foliage, and that picking time required per unit of crop is much less with open growth habit.
An inheritance study was inconclusive because of problems in progeny plant classification. It appears that growth habit is a complex of several characteristics, and as such, is inherited in a multigenic manner.
The objective of this study was to elucidate the genetic control of the semideterminate growth habit in tomato (Lycopersicon esculentum Mill.). A semideterminate tomato line was crossed with determinate and indeterminate lines; their F1, F2, and backcrosses were grown; and the growth habit recorded and analyzed. Plants with six or more inflorescences on the main stem were defined as semideterminate, while those with fewer were defined as determinate. The F2 and backcross to determinate were bimodal, indicating a single recessive gene for semideterminate, which was denoted as sdt. The goodness-of-fit chi square for a single recessive gene model was 88% and 69% for F2 and backcross generations, respectively. In the cross between semideterminate and indeterminate types, the results indicated control by two genes, sp and sdt, with the sp+ indeterminate type epistatic over semideterminate. The goodness-of-fit to this model was 70% and 82% for F2 and backcross generations, respectively.
growth habit, although trailing cultivars are desirable as they have increased their utility as ornamental plants for uses in hanging baskets and mixed containers, and as groundcover in the landscape. Trailing habits can be related to less or gradual loss
Prostrate growth habit (PGH) in tomato (Lycopersicon esculentum Mill.) lines derived from breeding material developed at the Agriculture Canada Research Station, Beaverlodge, Alberta, was the subject of a quantitative inheritance study. Plants with PGH have an increased lateral branch angle, relative to upright plants, and crown-set fruit supported above the soil surface making hand harvest easier. Genetic parameters were estimated in two families (20G and 53G), each containing PGH and upright-habit parental lines, F1, F2, and backcrosses to each parent. Field-grown plants were subjectively rated twice during the growing season. Broad-sense heritability of PGH in family 20G was estimated to be 0.65 and 0.71 for ratings of plant growth habit 6 and 9 weeks after transplanting, respectively, and 0.71 and 0.68 for those of family 53G. Narrow-sense heritability was estimated to be 0.83 and 1.05 for the two ratings in the 20G family and 0.77 and 0.78 in the 53G family. F1 and F2 means were not different from mid-parent values. The genetic variance was entirely additive and expression was influenced by the environment. The data did not support the hypothesis that PGH was controlled by a single gene.
available. We hypothesized that short-internode plants, which have a compact growth habit, are well-suited for weed management in an organic system. Compact plants develop a denser leaf canopy that may shade competing weeds. Nonsprawling vines may be easier
(‘SD22–59’) resembled the ‘A72’ dwarf and the segregation of growth habits in progeny of ‘SD22–59’ × standard growth habit varieties (1 semidwarf:1 standard growth) was also suggestive of the phenotype produced by the ‘A72’ mutation. To our knowledge
The contorted hazel, Corylus avellana `Contorta', is an ornamental tree prized for its grotesquely twisted trunk and branches. `Contorta' was discovered in a hedgerow in England about 1863 and has been commercially propagated by layerage or graftage because it was thought to not breed true from seed. We investigated the inheritance of contorted growth habit in the course of our work breeding hazelnuts. Crosses between normal growth habit cultivars and `Contorta' produce all normal seedlings. Sib matings of compatible normal seedlings of `Contorta' produce offspring in the proportion of 3 normal: 1 contorted. The backcross of a normal `Contorta' seedling to `Contorta' gives progeny in the ratio of 1 normal: 1 contorted, indicating control of the trait by a single recessive gene.