An agronomic and seed-quality evaluation of noug (Guizotia abyssinica Cass.) germplasm in Ethiopia

Noug (Guizotia abyssinica Cass.), a member of the Compositae family, is grown as an oilseed crop in Ethiopia. The crop grows best on poorly drained, heavy clay soils. This study investigates the genetic variability of agronomic and seed quality characteristics of 241 noug germplasm collections from different parts of Ethiopia evaluated in a field test at Ghinchi, near Addis Ababa, Ethiopia, in 1992. The maturity of the noug accessions ranged from 132 to 168 days. Seed oil contents ranged from 39.8 to 46.9% with linoleic acid being the major fatty acid of the oil (76.6% of total fatty acids). The results of this field study indicated that genetic differences for maturity existed among the noug accessions. Oil content variation was continuous, without clear separation of accessions into oil content groups. It is concluded that the genetic variation observed among these accessions could be utilized in a breeding programme to develop high-yielding, well-adapted, high-oil-content noug cultivars for production in Ethiopia.     

Highly efficient in vitro regeneration of the industrial oilseed crop Crambe abyssinica

A highly efficient regeneration protocol for oilseed crop Crambe abyssinica has been developed using hypocotyls as explants in this study. Crambe is a potential engineering oilseed crop for industrial purposes as it contains 55-60% erucic acid in its oil and, more importantly, it does not outcross with any food oil seed crops. However, the low regeneration frequency with the currently available protocols is still a limiting factor for genetic modification of Crambe. In this study, we investigated the effects of N-source, C-source, AgNO₃, cultural conditions as well as the concentration and combination of plant growth regulators (PGR) on the regeneration frequency of C. abyssinica. The results showed that all these factors, especially the N-source and PGR concentrations and combinations, played an important role in shoot regeneration. Among all the factors tested, the combination of using hypocotyls from C. abyssinica cv. galactica, the Lepiovre basal medium supplemented with 16 g l⁻¹ glucose, 0.5 g l⁻¹ AgNO₃, 2.2 mg l⁻¹ thidiazuron (TDZ), 0.5 mg l⁻¹ α-naphthaleneacetic acid (NAA), 2.5 g l⁻¹ Gelrite, seeds germinated in dark for 3 days and explants cultured in light, gave the best regeneration frequency (over 95%). The results also suggest that reducing the content of NH₄⁺ or keeping a suitable NO₃⁻/NH₄⁺ ratio in the regeneration medium would be crucial to Crambe shoot regeneration.     

海甘蓝的农学性状观察及评价

海甘蓝为一年生草本植物，适应性广，生育期短，丰产潜力大，脂肪和蛋白质含量较高．去壳种子的含油量为４４．４７％，并酸含量高达６２．５０％，比国外报道的结果高２．５％－７．５％，硫甙含量为７１．５１—８２．２μｕｍｏｌ／ｇ。理论产量９９—３５０ｋｇ／亩．在我国海甘蓝很有希望成为一种新型的高芥酸工业用油料作物。