Hybridization of diecious and monecious hemp
Len i Konoplja (Flax and Hemp). 7, 34-37
Pollination of southern diecious populations by southern monecious cultivars produced progeny almost entirely of plants; back crossing with a monecious cultivar gave 50% plants, the rest comprising gynomonecious and some ordinary male plants; in later generations the proportion of plants diminished and that of monecious increased, though in the F11 there were still 25.5% of, which had higher weights of seed per plant and of 1000 seeds; the proportion of plants depended mainly on the degree of isolation and of roguing. Progenies of plants of two F4 hybrids contained 39.6-41.1%, those of monecious, 17.6-32.4% and those of gynomonecious, 10.1-18.6%; the proportion of gynomonecious was also highest in the progenies of plants. In F1 progenies of the late-maturing Chinese diecious cultivar Luan with southern monecious, the growing period was 158 days and by the F7 had approached that of the southern parent; in similar progenies from Juznaja pavlogradskaja, the growing period diminished from 131 days in the F1 to 124 in the F7; yield of stems in the former hybrid was intermediate in the early generations and though it diminished in later ones it remained above that of southern monecious. Seed yield was higher than that of the parents, particularly in the F1 hybrids. By selection from hybrids of the above type, two cultivars have been produced: Juznaja odnovremenno-sozrevajuscaja 13 is early, good in seed yield and fibre quality; Dnepr 3 is later but has a higher fibre yield. Several cultivars have been selfed over a number of generations and crosses made between inbreds. (Breed. Exp. Sta., Sinel'nikovo, Ukrain.