Effects of transplanting and AMF inoculation on the fruit yield of African eggplants (Solanum aethiopicum and Solanum anguivi) in Tanzania

The African eggplant (Solanum aethiopicum L., Gilo group) is one of the most common traditional vegetables in Tanzania. The yield of the African eggplant in Tanzania is far lower than the potential yield expected, which is due primarily to biotic and abiotic stresses. We conducted experiments at two locations in Tanzania to study whether or not plant growth and the fruit yield of the Gilo group of African eggplant can be significantly improved through transplanting coupled with the inoculation of arbuscular mycorrhizal fungi (AMF) at sowing. Many plants, particularly for the directly sown treatment, died well before harvesting, and, in addition, many surviving plants showed symptoms of wilting. The transplanting of tray seedlings and using AMF inocula at sowing led to an overall significant increase in fruit yield by 30%–40% and 20%–25%, respectively. Increased fruit yield per experimental plot resulted primarily from a greater number of plants that survived and reached the harvesting stage. The exact effect of planting method (i.e., transplanting or direct sowing) and AMF inoculation, however, varied greatly with plant accessions. Further research is needed to understand the cause(s) for plant mortality in order to develop appropriate plant management practices

The World Vegetable Center Amaranthus germplasm collection: Core collection development and evaluation of agronomic and nutritional traits

Amaranth (Amaranthus spp.) is an underutilized crop increasing in popularity as a grain and as a leafy vegetable. It is rich in protein, minerals, and vitamins, and adapts well to a range of production systems. Currently, the lack of improved cultivars limits the use of the crop. Breeding-improved cultivars requires access to large collections of amaranth biodiversity stored in genebanks. The task of searching such vast collections for traits of interest can be eased by generating core collections, which display the diversity of large collections in a much smaller germplasm set. The World Vegetable Center amaranth collection contains around 1,000 accessions of 13 species; among them, there are 281 accessions of four species important for use as vegetable amaranth in Africa (A. cruentus, A. hypochondriacus, A. caudatus, and A. dubius). Based on single nucleotide polymorphism (SNP) marker genotype diversity, a core collection (CC) of 76 accessions, cultivars, and selections was assembled. To a large extent, it represents the diversity of the whole collection. The CC was evaluated for yield and nutritional parameters during the cool and warm seasons in Tanzania and Taiwan and a pretest for variation of drought tolerance in the CC has been performed. Cultivar Madiira 2, an improved cultivar developed for vegetable production in Africa, outperformed all other tested cultivars in terms of yield stability, but several CC accessions had higher yield, lower wilting score, and higher nutrient content than Madiira 2. This indicates the core collection can be used for further improvement of amaranth cultivars