Variations in morphological and agronomic traits among Jerusalem artichoke (Helianthus tuberosus L.) accessions

Jerusalem artichoke is a diversely-utilized crop. Selection for high yield, inulin content and other economically important traits are useful for improving this crop. The objectives of the present study were to evaluate genetic variability for qualitative and quantitative traits among Jerusalem artichoke accessions and to identify different groups of accessions using morphological and agronomic traits. Seventy-nine accessions were evaluated in a randomized complete block design with two replications in the late rainy season 2008, the early rainy season 2009 and the late rainy season 2009 at Khon Kaen University agronomy farm, Thailand. Morphological and agronomic characteristics were evaluated for genetic variations. High variations were found among Jerusalem artichoke accessions for qualitative and quantitative characters, and selection for these characters is possible. High variations were observed for tuber width, number of tubers/plant, biomass, fresh tuber yield and tuber size. Correlation coefficient between fresh tuber yield and tuber size was positive and significant (0.58, P ≤ 0.01). Improvement of tuber size is a means to improve yield and tuber quality. Based on morphological and agronomic characteristics, Jerusalem artichoke accessions were clustered into four distinct groups (R² = 0.88). These groups may be used as parental material to generate progenies for further improvement of this crop. This information will enable breeders to make informed decisions about possible heterotic groups for their breeding programs and germplasm conservation.     

A new norhopane from Harpullia arborea

A new norhopane triterpenoid, 3beta-eicosanoyl-6beta-hydroxy-21alphaH-24-norhopan-4(23),22(29)-diene (1), was isolated from the leaves of Harpullia arborea. The structure of the compound was determined by spectroscopic methods.     

Genotypic variability and genotype by environment interactions for inulin content of Jerusalem artichoke germplasm

Genetic variations in germplasm and genotype × environment interaction (G × E) are important for crop improvement. The objectives were to explore genetic variation in Jerusalem artichoke germplasm and to evaluate G × E interaction for inulin content. Seventy-nine accessions of Jerusalem artichoke were evaluated in a randomized complete block design with two replications for three seasons. Significant variation in inulin content (55.3–74.0% dry weight) was observed and the genotypes with high inulin content could be identified although there was intermediate G × E interaction. Genotypes were also significantly different for days to maturity, fresh tuber yield, biomass and harvest index and G × E interactions for these traits were also significant. The correlation between inulin content and days to maturity was not significant (r = −0.20), whereas inulin content and fresh tuber yield were significantly associated (r = 0.22). JA 37 and CN 52867 are promising for high yield and inulin content.