Evaluation of the World Collection of Safflower, Carthamus tinctorius L. IV. Yield and Yield Components and Their Relationships¹

Abstract

A study of a collection of 903 varieties of safflower (Carthamus tinctorius L.) for the mean yield per plant and the three major yield components, number of heads per plant, number of seeds per head, and seed weight, revealed marked differences in the potential of lines from different origins. Because of the mutual compensation of the yield components, the differences in yield were not as marked as they were for the components. The collection contains an abundance of genetic variability which is available for breeding higher‐yielding safflower varieties. There were regional differences in the components due to human and/or natural selection.A multiple stepwise regression analysis showed that the most important yield component was the number of heads per plant. The number of seeds per head was of little importance, except for lines from Iran. Seed weight had no effect on yield per plant, except for a minor influence in the Iranian lines. The number of heads per plant had negative but negligible correlations with oil content. Yield per plant was not correlated with season length or oil content. Since the findings were obtained under spaced nursery conditions, they are not necessarily applicable directly to dense field stands.

Evaluation of the germ plasm collection of safflower, Carthamus tinctorius L. V. Distribution and regional divergence for morphological characters

“…It was designed to evaluate the whole collection for the first time for resistance to insect pests and to some diseases as well as for regional divergence, and to identify geographical centers of desirable traits (ASHRI, 1973). Divergence was found for certain yield components (ASHRI et al, 1974), oil content (AsHRI et al, in press) and disease reaction (ASHRI, 1971a). In the present paper, the extent of divergence and the distribution of 13 morphological traits will be examined.…”

Evaluation of the germ plasm collection of safflower, Carthamus tinctorius L. VII. Variability of capitulum width and outer involucral bracts' dimensions

“…However, the latter is a minor and unimportant component of yield (AsHRI, 1973 ;ASHRI et al, 1974). The other correlations with head diameter are low even when significant (Table 2).…”

“…The germ plasm collection of safflower and the separate regional pools possess considerable variability for OIB length and width and for primary head diameter (Table 1), as they do for other traits (AsHRI, 1971;ASHRI, 1973;ASHRI et al, 1974). Some geographical clines were discerned, indicating possible gene flow.…”

“…In the whole collection, OIB width gave highly significant but low correlation values with four variables (Table 2) but this was not the case in the separate analysis for the lines from Iran and Egypt. Even if the correlation values of OIB width with the number of seeds per head and seed weight were very high, they would still have little impact on breeding for yield because the number of seeds/head and seed weight have a minor effect on yield (ABEL, 1969 ;ASHRI et al, 1974). Similarly, the OIB length correlations are not very helpful in breeding for higher yield and oil content (Table 2).…”

“…Wide heads were reported to occur in Afghanistan and neighboring countries (KuPsow, 1932) and Egypt (KNOWLES, 1958;WEISS, 1971). Head diameter was shown to have a very minor contribution to yield in the germ plasm collection used for the present study (ASHRI, 1973;ASHRI et al, 1974).…”