QUANTITATIVE-ANALYSIS OF LINUM-USITATISSIMUM CROSSES FOR DUAL-PURPOSETRAITS

The commercial future of Linum usitatissimum is intrinsically linked t o its cultivation as a dual-purpose crop for producing increased seed and fibre yields. The present study evaluates 36 F-1 crosses derived f rom nine linseed/flax accessions for their potential as dual-purpose c ultivars and/or their suitability for extracting new recombinants prod ucing high seed yield as well as increased fibre output. The quantitat ive analysis indicated that variation between the F-1 families is larg ely but not exclusively due to the additive and non-additive (dominanc e) effects of genes. Dominance is high for plant height (H1), height a t maturity (HMT), number of branches (NBr) and seed weight (SdWt) whil e 100 seed weight (Wt100) displays no dominance at all. The repeatabil ity estimates representing the heritability of each trait, vary from l ow (0.20) for number of branches (NBr) to high (0.71) for height at fl owering time (HFT). The dual-purpose traits such as seed weight (SdWt) and straw weight (StWt) were only moderately inherited while flowerin g time (FT) and various heights were rather highly heritable. A modera te and positive correlation (r = 0.57) between StWt and SdWt, and a co mpletely independent inheritance of Wt100 suggested that there are goo d chances of combining these traits into a single genotype. The phenot ypic performance of the crosses also confirmed this tread and at least four crosses showed superior performance for both SdWt and StWt compa red to their parental lines. All these crosses involved a linseed line (B3) as a common parent and the second parent was either another lins eed line (Al and A3) or a flax accession (K3 and L2); none of the flax x flax crosses showed good potential for seed yield. While all four c rosses possess the potential to become highly productive, dual-purpose , hybrid varieties, the extraction of desirable inbred lines from them , however, may prove difficult because the superior performance of the hybrids seems largely due to strong unidirectional dominance and high SCA effects.