In Vitro Tissue Culture S tudies in Sunflower (Helianthus spp.)

Abstract

Sunflower (Helianthus annuus L.) is the fourth mos t important oilseed crop in the world in terms of total yearly production,after soybean, rapeseed, and groundnut. The classical breeding s tudies made from 1880 until today have beenfocused on major characters, such as high fat, pes ts and diseases resis tance. The narrow genetic base in sunflowercauses a major problem at breeding and selection of desired sunflower lines eg. cytoplasmic male s terility, disease andinsect pes t resis tance, fertility-res toration, agronomic and seed-oil characteris tics, drought tolerance, protein content,imidazolinone resis tance and fatty acid composition. The growth or maintenance of cells, tissues, organs, and theircomponents under defined physical and chemical conditions in vitro described as plant tissue culture, is an importanttool in both basic and applied researches as well as in commercial application. The firs t and important s tep of tissueculture is development of in vitro regeneration sys tem. Researchers have successful attempts by various explants, suchas immature embryo mature embryo, meris tem, anther, hypocotyl, protoplas t, cotyledonand embryo sac. Although thespecific techniques like, embryo culture, organogenesis, somatic embryogenesis have been succesfully used, antherculture, microspore culture ovule cultureneeds to be improved.