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  • Author or Editor: J. Reynolds x
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Abstract

Apios americana Medikus, a nitrogen-fixing, viny legume that produces seeds and tubers is being evaluated as a food crop. About 2500 plants obtained from colchicine-treated and nontreated seeds, tubers from wild sites, and plants derived from tissue culture were cultivated on a silt loam soil. Two tuber-derived plants (probable clone) yielded an average of 3.747 kg and another seed-produced plant yielded 2.170 kg of tubers per plant. Plants were also found that produced mostly rhizomatous material without tubers, only fleshy roots, fleshy roots and tubers, and only tubers. More than 400 pods per plant were observed from some plants, although seed abortion greatly reduced seed yield of many otherwise normal-looking pods.

Open Access

Abstract

Plantlets have been produced by germination of somatic embryos derived from callus of Hibiscus acetosella Welw. ex. Hiern. Five of the media used were based on Nitsch and Nitsch's Medium H (purchased formulated without IAA or sucrose). To this base were added, per liter: 40 g glucose for NH; 10 g sucrose for NH-1; 40 g sucrose, 1 mg 2,4-dichlorophenoxyacetic acid (2,4-D), and 1 mg 6-furfurylaminopurine (kinetin) for RM-1; 40 g glucose, 250 mg NaH2PO4·H2O, 28 mg FeC6H5O7·nH2O, 100 mg i-inositol, 30 mg adenine, 0.1 mg (2-chloroethyl)trimethylammonium chloride (chlormequat), and 4 mg 2,4-D for SEM-1; and 40 g glucose, 0.1 mg chlormequat, 0.05 mg B-napthoxyacetic acid (NOA), and 10 mg 2-isopentyladenine (2iP) for HC. The B5 medium was Gamborg's B5 without 2,4-D. All media contained 8 g agar and had the pH adjusted to 5.7 prior to autoclaving. Primary explants placed on HC produced adventitious shoots and callus. When callus explants from HC or primary explants of roots were placed on RM-1, a callus containing embryoid-like structures was produced. Torpedo stage embryos were induced by subculturing this callus from RM-1 on SEM-1 and could be proliferated by sequential transfer from SEM-1 to RM-1, then back to SEM-1. When callus containing torpedo-stage embryos was transferred to B5, the embryos germinated and produced rudimentary plantlets with elongated hypocotyls, short roots, and small cotyledons. These developed into plants when transferred to NH-1.

Open Access

Abstract

Shoot regeneration has been obtained from leaf and/or cotyledon explants of winged bean [Psophocarpus tetragonolobus (L.) D.C.], Hibiscus acetoseiia Welw. ex. Hiern, muskmelon (Cucumis melo L.), and watermelon [Citrullus lanatus (Thunb.) Mat-sum & Nakai] on 2 media designated HC and BR-1.

Open Access

Abstract

A consistent desire for a uniquely flavored seedless table grape has prompted the release of ‘Simone’. Unlike its sister seedling ‘Sovereign Coronation’ (Denby, 1977), ‘Simone’ possesses a very mild labruscana flavor character. It is a blue, seedless, midseason table grape that matures at Summerland in late September.

Open Access

Shoots were regenerated from callus of Apios americana Medikus (apios, groundnut) using internodal explants from in vitro-germinated seedlings and from sprouted tubers on a modified Murashige and Skoog (MS) basal medium. Shoot regeneration was observed over a range of 2iP and IBA combinations. GA3 increased the number of shoots regenerated per epicotyl explant. The most efficient regeneration (≈90%) was with internodal epicotyl explants on 100 μm 2iP, 0.5 μm IBA, and 1.5 μm GA3. Regenerated shoots were rooted on liquid and solid MS medium with 0.5 μm IBA; however, rooting was more successful on the liquid medium. About 60% of rooted plants were successfully established in pots. Chemical names used: N-(3-methyl2-butenyl)-1 H-purin-6-amine (2iP), 1 H-indole-3-butanoic acid (IBA), gibberellic acid (G A3).

Free access

Shoot proliferation from axillary buds of Apios americana Medikus (apios, groundnut) was obtained on a modified Murashige and Skoog (MS) medium supplemented with 2.22 μm BAP, 0.5 μm IBA, and 3.0 μm GA3. Existed shoots rooted on MS basal medium. About 60% of the rooted plants were successfully established in soil. Chemical names used: 1 H-indole-3-butanoic acid (IBA). gibberellic acid (GA3), N6-benzylaminopurine (BAP).

Free access

Abstract

Pooled data from several cultivars of highbush blueberry (Vaccinium corymbosum L.) and rabbiteye blueberry (V. ashei Reade) showed a highly significant correlation between fruit size and developed seed content although there were exceptions of individual cultivars means. Fruit size and seed no. decreased with progressively later harvests in all cultivars. Seed size differed among the various cultivars but was not related to fruit size. The % of total seeds that developed varied among cultivars and was correlated with fruit size.

Open Access

Many seed companies are using plant biotechnology as a valuable extension of conventional plant breeding with the goal of providing breeders with novel biological traits. The application of biotechnology allows scientists and breeders to make precise changes during the process of germplasm improvement. Many of the first improvements achieved using transgenic plants have involved the transfer of input traits. Some of these traits include, insect resistance, nematode resistance, disease resistance, and herbicide tolerance. For example, the insertion of a gene that produces the crystalline toxin from Bacillus thuringeinsis has led to the production of transgenic plants that are resistant to insects from the Order Lepidoptera. The transfer of coat protein genes from plant viruses has lead to the development of transgenic crops that are resistant to the virus from which the gene or genes were isolated. Various strategies have been developed that allow transgenic plants to tolerate applications of herbicides that allows for improved weed control. In addition to input traits, other strategies are now being used that are directed at improving output traits. These include such traits as enhanced shelf life, ripening control, altered oils, and superior processing characteristics. At Seminis Vegetable Seed Co., we are currently developing transgenic plants with enhanced input as well as output traits. We have an active program using pathogen derived genes to develop virus resistance cultivars in a range of crops including, tomato, cucurbits, and peppers. Using this approach, we have been able to develop plants with multiple virus resistance by transforming germplasm with constructs containing stacked genes. Seminis is currently marketing a hybrid squash variety with resistance to two major virus pathogens. Another major goal for Seminis is implementing biotechnology to improve various aspects of fruit quality including viscosity, color, softening, and shelf life. Through our collaboration with Zeneca we have developed a high viscosity tomato, which was produced by suppressing endogenous levels of polyglacturonase. This processed food product is currently on the market in the United Kingdom.

Free access