Modification of quantity and quality of safflower oil through plant breeding

Assaying polymorphism at DNA level for genetic diversity diagnostics of the safflower (Carthamus tinctorius L.) world germplasm resources

Carthamus tinctorius (2n = 2x = 24), commonly known as safflower, is widely cultivated in agricultural production systems of Asia, Europe, Australia, and the Americas as a source of high quality vegetable and industrial oil. Twenty-two RAPD primers, 18 SSR primers, and 10 AFLP primer combinations were used to assess: (1) the genetic diversity of 85 accessions (originating from 24 countries) representing global germplasm variability of safflower and (2) the interrelationships among safflower 'centers of similarity' or 'regional gene pools' proposed earlier. The RAPD and SSR primers and AFLP primer combinations revealed 57.6, 68.0, and 71.2% polymorphism, respectively, among 111, 72, and 330 genetic loci amplified from the accessions. The sum of effective number of alleles (66.44), resolving power (59.16), and marker index (51.3) explicitly revealed the relative superiority of AFLP as a marker system in uncovering variation in safflower. Overall, AFLP markers could recognize 'centers of similarity' or 'regional gene pools'. Analysis of molecular variance and Shannon's information index provided corroborating evidences for the present and previous studies that concluded fragmentation of safflower gene pool into many gene pools. Divergent directional selection is likely to have played an important role in shaping the diversity. From the practical applications standpoint, the diversity of Iran-Afghanistan gene pool is very high, equivalent to the total diversity of the species. The Far East gene pool is the least diverse. The present comprehensive input, first of its own kind in safflower, will assist marker based improvement programmes in the crop.

Genetic analysis of seed yield, oil content and their components in safflower (Carthamus tinctorius L.)

The genetic architecture of seed yield, oil content and their components was studied in a diallel cross of F1 and F2: eleven parents, representing an adequate diversity for all considered characters in safflower were used. Combining ability analysis revealed the predominance of gca variance for plant height, total capitula, seed weight, seed number and seed yield in F1 and F2 generations and for days to flowering and oil content in F1. The analysis of components of variance indicated that the non-additive factor was the major influence on total capitula and seed yield in F1s, and F2s, and on plant height, seed weight and seed number in the F2 alone. The heterogeneity of the dominance component over generations has been attributed to coupling phase linkage. All four Indian parents, namely S 144, A1, MS 49 and 6 spl, together with G 1157 and US 104 in the exotic group, were the best combiners for seed yield and/or for one of its components while the remainder of the exotic parents were characterized by high gca effects for oil content. VFstp 1 and Frio were the only parents approximating both properties of oil content and seed yield. Breeding methods, such as biparental mating followed by reciprocal recurrent selection, were suggested for the simultaneous improvement of seed yield and oil content.

An analysis of association of components of yield and oil in safflower (Carthamus tinctorius L.)

Inter-relationships of various component characters with yield and oil content were analysed using 215 entries of safflower from India and U.S.A. Correlation of capsule number per plant and capsule weight with yield per plant was pronounced and they showed large direct effects on yield. All other components influenced seed yield mainly through these two components. Seed size had little effect on yield while seed number exerted a positive influence. The proportion of hull expressed as per cent of the whole seed revealed a highly significant and inverse relationship with oil content and was mainly responsible for the observed variability in oil content in the material. Although negative association was indicated between seed size and oil content, it was observed to be due to the indirect effect of hull content and not due to direct effect of seed size. Interestingly, yield per plant and its major components, number of capsules and capsule weight, revealed a negligible relationship with oil content. Both direct as well as indirect effects of hull percent and yield per plant were responsible for the favourable effect of seed number on oil content. The correlation of plant height, days to first flowering and total crop growth period with yield and oil content was either negligible or low, offering scope for developing early maturing and dwarf varieties with high yield and oil content. Spine index showed a non-significant association with yield and oil content. Capsule number, capsule weight and hull per cent were observed to be the most important components in breeding for higher yield and oil content.