Cucurbit Genetics Cooperative Report 10:92 (article 50) 1987
J. W. Shail and R. W. Robinson
Horticultural Sciences Department, New York State Agricultural Experiment Station, Geneva, NY 14456
Previous attempts to grow plants from cultured anthers have been successful for cucumber (3) and muskmelon (2) but not for squash (1). We found that squash pollen did not respond, other than to form pollen tubes, but longitudinal anther segments developed callus growth in vitro. Best results were achieved with anthers 10 to 20 mm in length. Murashige and Skoog medium with 1 or 2 ppm 2,4-D was more successful than the other media tested, and NAA (2 ppm) plus benzyl adenine (3 ppm) encouraged differentiation. Explants on solid media (0.8% agar) developed better than those in liquid on a rotary shaker.
Squash varieties differed in callus formation and differentiation on this medium. ‘Gold Nugget’ anthers developed a moderate amount of callus, more than the other C. maxima cultivars tested (Buttercup, Emerald, Oregold, and NK 530). C. moschata cv. Butternut, unlike ‘Waltham Butternut’ and ‘Ponca’, consistently developed callus from cultured anthers. All C. pepo cultivars tested (Straight Neck, Caserta, Lady Godiva, Scallop, Table Queen, and Cinderella) produced callus, but the nature of the callus and tissue formation differed for each cultivar. Best differentiation occurred with ‘Scallop’ and ‘Cinderella’. Root formation occurred, particularly with ‘Buttercup’and ‘Scallop’. Shoot formation also occasionally occurred with these cultivars, but plantlets were not obtained. It was not determined if the cultured cells were haploid and of pollen origin, or diploid and derived from the anther wall.
Excised ovules of C. pepo cultivars Scallop and Early Prolific Straightneck did not respond well to tissue culture, but ‘Black Jack’ ovules developed prolific callus growth. Organized growth developed subsequently from the callus, but plantlets were not obtained.
Ovules excised from C. pepo cv. Black Jack, 24 to 72 hrs after pollination with C. ecuadorerensis, produced callus and roots but not plants when cultured. The interspecific hybrid was obtained, however, by culturing embryos from mature fruit.
Literature Cited
- Chang, Yin-Fu. 1981. Anther culture of Cucurbita pepo L. Thesis, Texas A & M Univ., College Station, TX.
- Dryanovska, 0. A. and I. N. Ilieva. 1983. In vitro anther and ovule cultures in muskmelon (Cucumis melo L.). Compt. Rend. Acad. Bulgre Sci. 36:1107-1110.
- Lazarte, J. E. and C. C. Sasser. 1982. Asexual embryogenesis and plantlet development in anther culture of Cucumis sativus L. HortScience 17:88.