Genome scan identifies flowering-independent effects of barley HsDry2.2 locus on yield traits under water deficit

Increasing crop productivity under climate change requires the identification, selection and utilization of novel alleles for breeding. We analyzed the genotype and field phenotype of the barley HEB-25 multi-parent mapping population under well-watered and water-limited (WW and WL) environments for two years. A genome-wide association study (GWAS) for genotype by-environment interactions was performed for ten traits including flowering time (HEA), plant grain yield (PGY). Comparison of the GWAS for traits per-se to that for QTL-by-environment interactions (QxE), indicates the prevalence of QxE mostly for reproductive traits. One QxE locus on chromosome 2, Hordeum spontaneum Dry2.2 (HsDry2.2), showed a positive and conditional effect on PGY and grain number (GN). The wild allele significantly reduced HEA, however this earliness was not conditioned by water deficit. Furthermore, BC2F1 lines segregating for the HsDry2.2 showed the wild allele confers an advantage over the cultivated in PGY, GN and harvest index as well as modified shoot morphology, longer grain filling period and reduced senescence (only under drought), therefore suggesting adaptation mechanism against water deficit other than escape. This study highlights the value of evaluating wild relatives in search of novel alleles and clues to resilience mechanism underlying crop adaptation to abiotic stress.HighlightA flowering-time independent reproductive advantage of wild over cultivated allele under drought identified in a barley GWAS for genotype-by-environment interactions, with modified shoot morphology, reduced senescence and longer grain filling

Biomass Production of Root and Shoot of Talinum paniculatum Gaertn. by Liquid and Solid Ms Medium with Plant Growth Hormone IBA

Talinum paniculatum Gaertn. is one of traditional medicinal plant in Indonesia which has benefits such as for vitality and maintain blood circulation. The aim of this research is to obtain biomass production of root and shoot of T. paniculatum Gaertn. by liquid and solid MS medium with IBA. This research conducted to provide biomass as raw material for secondary metabolites test. Stems as explant were induced with four treatments (liquid MS, solid MS, liquid MS + 2 ppm IBA and solid MS + 2 ppm IBA) with five repetitions. Observation did for 28 days. The parameters are the percentage of explants which formed the root and shoot, morphology, fresh and dry biomass. Result shows that percentage of root and shoot have 100% in liquid and solid MS + 2 ppm IBA. Fresh and dry biomass of root and shoot in solid MS + 2 ppm IBA higher than the others. This research found callus in liquid and solid MS + 2 ppm IBA. Morphology of root in liquid MS has thin and friable, but thick in solid MS. Shoot in solid and liquid MS has thin, short and sturdy.

Allometric relationships for vegetative growth flush in pruned stems of macadamia (Macadamia integrifolia): effects of carbohydrate source and season

Hedging is used to control tree size in macadamia orchards, but the effects on subsequent shoot growth and floral initiation may impair fruit production. Four-year-old grafted macadamia (Macadamia integrifolia Maiden & Betche) trees were subjected to pruning of the most recent seasonal shoot in autumn and spring. Factorial combinations of treatments included girdling or not girdling near the base of the previous season’s (parent) shoot; removal of all except two, four or six leaves from the parent shoot; and defoliation or no defoliation of the shoot that appeared after pruning. Initial numbers and dimensions of flush-shoot internodes were similar for all branch treatments in autumn and for girdled branches in spring, and were smaller than half those for non-girdled stems in spring. Later flush-shoot growth depended on the number of leaves retained on the parent shoot, the presence or absence of a connection to the tree below the parent shoot, and on the season, declining with limiting growing degree-days in winter and accelerating with increasing growing degree-days in summer. In both seasons, reserves beyond the parent (previous season’s) shoot contributed the major source of carbohydrate for continuing flush-shoot growth, and particularly the growth of leaves. The combinations of seasonal conditions, shoot parameters before the commencement of flush-shoot growth, and flush-shoot morphology permit the inference of allometric relationships that can be applied to the quantitative modelling of vegetative shoot morphology and growth in macadamia.