Resequencing 250 soybean accessions: new insights into genes associated with agronomic traits and genetic networks

Limited knowledge on genomic diversity and the functional genes associated with soybean variety traits has resulted in slow breeding progress. We sequenced the genome of 250 soybean landraces and cultivars from China, America and Europe, and investigated their population structure, genetic diversity and architecture and selective sweep regions of accessions. We identified five novel agronomically important genes and studied the effects of functional mutations in respective genes. We found candidate genes GSTT1, GL3 and GSTL3 associated with isoflavone content, CKX3 associated with yield traits, and CYP85A2 associated with both architecture and yield traits. Our phenotype-gene network analysis revealed that hub nodes play a role in complex phenotypic associations. In this work, we describe novel agronomic trait associated genes and a complex genetic network, providing a valuable resource for future soybean molecular breeding.

Not only the seed matters: Farmers’ perceptions of sources for banana planting materials in Uganda

The adoption of improved seed and other planting material in developing countries shows mixed results despite their potential to increase agricultural productivity. To arrive at a better understanding of the observed adoption rates, a lot of research is focused on finding the cultivars and variety traits that are attractive to farmers. Given smallholder farmers’ seed sourcing practices are often influenced by social ties and cultural norms, it is also relevant to understand where and why farmers seek to acquire planting material. In this study, means-end chain analysis was applied to understand farmers’ perceptions of formal and informal sources of banana planting material. Means-end chain analysis allows respondents to select and verbalize their own constructs to evaluate a product or service. These personally relevant constructs are subsequently linked to their personal goals via laddering interviews. We interviewed 31 Ugandan banana farmers from Western and Central region. Farmers associated formal sources mainly with improved cultivars, tissue culture plantlets and low levels of diversity. Informal seed sources were mostly associated with traditional cultivars, suckers and high levels of diversity. The goals farmers pursued while acquiring planting material, such as financial gains, food security, and to sustain and develop the household, were fairly similar among different groups of farmers. The means through which farmers aimed and preferred to pursue these goals differed and could be related to aspects such as gender, production scale and production goals. These differences among farmers preferences for particular sources indicate that not only cultivar traits should be tailored to farmers’ preferences and needs, but also the characteristics of the sources from which farmers access planting material.

PROBLEMS OF COTTON SEED STOCK PRODUCING IN THE VARIETIES OF GOSSYPIUM HIRSUTUM

Radically enhancing of employed technologies on the growing of agricultural crops in Uzbekistan and quality of varieties has become one of the major challenges in the state priority today. Because, in the example of cotton plant as the principle crop, the republic is remaining far behind on cotton raw productivity -12th , and on cotton fiber productivity-29th than cotton producing countries. At this term, the state is a head reformer extending all scientific-technical and organizing measurements for the development of this field. The results on the study of seed stock cotton varieties’ cultivation for two years (2018, 2019) in the Burkhon farm, Navoiy division of Oqqorgon district, Tashkent region were presented in this paper. Planting quality, influences of seeds on the seed sprouting period, field germination of seed stocks, optimal seed stock expenditure, optimal seedling density, plants’ development and dynamics of yield components setting were studied in the field observations. It was identified that the used drill has planted at minimum, from 9 and maximum, up to 29 seeds per 1 m of a row. Coefficient of variation, according to the outcome of statistical analysis on the determination of difference between these two indexes has made of 29.7%. Field germination, height of plants, instability on the plants’ boll numbers and share of contamination in the variety traits of varieties were also analyzed and the necessary recommendations on new innovative ideas and technologies for improving of cotton seed production in grooving varieties and producing of seed stocks were given. KEYWORDS: Cotton, seed, germination, seed stock, technology, sprouts, variety, Sultan, S-6524.

How does Farmer Preference matter in Crop variety Adoption? The case of Improved Cassava varieties’ Adoption in Ghana

Ghana’s National Agricultural Research Systems have officially released 24 improved cassava varieties, which are high yielding, disease and pest resistant and early maturing. However, adoption of these varieties by mainly smallholder farmers is very low, leading to low yields and incomes. The purpose of this study was to contribute to the development and adoption of improved cassava varieties by assessing the preferences of farmers for cassava variety traits. The study explored Ghanaian cassava producers’ decision-making behaviour towards variety selection and the values they place on different cassava traits. It employed mixed logit and latent class models to estimate the values place on cassava traits, by using choice experiment data of 450 cassava producers from Ghana. Results revealed farmers’ preferences for longevity of root storage in the soil and disease resistance traits of cassava. The latent class model revealed that male youths were more likely to participate in improved varieties that take into account in-soil storage and multiple usages. The need for agricultural research systems to focus on other traits in addition to high yielding and disease resistance in order to boost adoption and increase production is imperative.

Grapevine varieties exhibiting differences in stomatal response to water deficit

Knowledge on variety traits and physiological responses to stress is still scarce in Vitis vinifera L., limiting the optimisation of irrigation and breeding for high water use efficiency. We have characterised five grapevine varieties using thermal imaging, leaf gas exchange, leaf morphology and carbon isotope composition. Plants of the varieties Aragonez, Trincadeira, Cabernet Sauvignon, Syrah and Touriga Nacional were grown in field conditions. Two experiments were performed. In Experiment I (2006), vines of Aragonez and Trincadeira were either well irrigated (WI, 80% ETc), non-irrigated but rain fed (NI) or subjected to regulated deficit irrigation (RDI, 40% ETc) and studied along the summer season. In Experiment II (2006 and 2007), vines of the five varieties were subjected to RDI (30–40% ETc) and studied at veraison. In Experiment I, leaf temperature (Tleaf) correlated negatively with stomatal conductance (gs) and leaf water potential (Ψpd). The inverse relationship between gs and Tleaf was highly significant in the afternoon. In Experiment II, the different genotypes showed different Tleaf for similar Ψpd. Stomatal density did not correlate with gs suggesting that varieties have different stomatal control. Our results show that combined measurements of canopy temperature and Ψpd can aid in better understanding of stomatal regulation in different grapevine varieties. Such variation in stomatal regulation should be taken into account in determining irrigation strategies.