ACHIEVEMENTS AND FUTURE-DIRECTIONS OF SUNFLOWER BREEDING

Sunflower (Helianthus annuus L.) is among the most important oil crops in the world. Due to its low to moderate production requirements, high oil quality, protein content, and utilization of all plant parts, it is grown on about 14 million ha. The major sunflower-producing countries in the world are the Soviet Union, Argentina, China, the United States, France, Spain, Romania, Turkey and Hungary. Sunflower became an oil crop around the end of the 19th century, when 'popular selection' was practiced in several parts of Russia to improve sunflower populations grown at that time. The most important contributions to the development of sunflower were made by Pustovoit and Jdanov in the Soviet Union, who increased the oil concentration in sunflower seed above 500 g kg-1. Leclercq of France discovered the first usable source of cytoplasmic male sterility in a cross H. petiolaris Nutt. X H. annuus L. and Kinman of the United States developed fertility restorer lines RHA 265 and RHA 266 which allowed practical development of sunflower hybrids. When starting a breeding program, it is useful to design a model of the desired hybrid and then strive to develop the envisaged model as closely as possible. It is also advisable to direct breeding efforts toward a limited number of economically important traits. These should include: (1) components of seed and oil yield: the number of seeds per plant, test weight, 1000-seed weight, low husk content and high oil concentration in the seed; (2) architecture of the sunflower plant: plant height, head size and shape, angle of the head, leaf area and leaf canopy; (3) increased harvest index: oil quality, protein concentration and quality, early maturation, short stem and uniform height; and (4) resistance to diseases and drought using wild sunflower species. Mass selection, a method of selecting desirable plants from a population on the basis of phenotypic traits, is still an effective method in sunflower breeding. Recurrent selection appears to be a promising method of increasing the frequency of desirable genotypes in a source population. Genetic variability of the cultivated sunflower may be increased by interspecific hybridization with wild sunflower species. The inclusion of wild species in breeding programs is difficult because of differences in chromosome number (2n, 4n, 6n) and incompatibility. These obstacles have been overcome by embryo culture and other tissue culture techniques. Generally, the use of new technologies in sunflower breeding is imperative, particularly in regard to the introduction of resistance genes to diseases and insect pests.