Photoperiod-sensitive male-sterile mutant in tomato and its potential use in hybrid seed production

• Published in: The journal of horticultural science & biotechnology 2004, Vol.79 (1), p.138-141
• Main Author: Sawhney, V.K
• Format: Article
• Language: English
• Subjects: androecium; hybrids; mutants; photoperiod; plant breeding; plant fertility; seed productivity; Solanum lycopersicum var. lycopersicum; tomatoes
• ISSN: 1462-0316; 2380-4084
• DOI: 10.1080/14620316.2004.11511726

The current practice of manual emasculation of tomato ¯owers for hybrid seed production is labour-intensive and contributes signi®cantly to the high cost of seed. Here we report on a photoperiod-sensitive, single gene male-sterile mutant (7B-1) in tomato which is 100% male sterile in long days (LD, minimum of 12.h daylength) in summer ®eld conditions, but produces many male-fertile ¯owers in short days (SD, 8.h). In LD, 7B-1 ¯owers contain stamens that are pale, short and in the anthers microspore mother cells are differentiated but meiosis does not occur, i.e. microspores and pollen grains are not formed. Unlike the wild type ¯owers, the style and stigma of 7B-1 ¯owers are well exposed and this allows for ready access for pollination without emasculation. In SD, mutant ¯owers possess normal-looking orange-yellow anthers that enclose the stigma and produce normal viable pollen, which when used for pollination of 7B-1 ¯owers yield good fruit- and seed-set. The 7B-1 seed in turn generate a 100% population of male-sterile plants all of which can be used as female parents for hybrid seed production. The female fertility is not affected in 7B-1 ¯owers in both LD and SD conditions. The 7B-1 mutant has been grown in various ®eld locations including, Saskatoon, California, Florida and in Chile, and at all locations it has shown stable male sterility. The 7B-1 mutant is a simple, natural and costeffective system that has a strong potential for use in commercial-scale production of tomato hybrid seed.