Genetic diversity and population structure of ridge gourd (Luffa acutangula) accessions in a Thailand collection using SNP markers.

This study explored a germplasm collection consisting of 112 Luffa acutangula (ridge gourd) accessions, mainly from Thailand. A total of 2834 SNPs were used to establish population structure and underlying genetic diversity while exploring the fruit characteristics together with genetic information which would help in the selection of parental lines for a breeding program. The study found that the average polymorphism information content value of 0.288 which indicates a moderate genetic diversity for this L. acutangula germplasm. STRUCTURE analysis (ΔK at K = 6) allowed us to group the accessions into six subpopulations that corresponded well with the unrooted phylogenetic tree and principal coordinate analyses. When plotted, the STRUCTURE bars to the area of collection, we observed an admixed genotype from surrounding accessions and a geneflow confirmed by the value of FST = 0.137. AMOVA based on STRUCTURE clustering showed a low 12.83% variation between subpopulations that correspond well with the negative inbreeding coefficient value (FIS = - 0.092) and low total fixation index (FIT = 0.057). There were distinguishing fruit shapes and length characteristics in specific accessions for each subpopulation. The genetic diversity and different fruit shapes in the L. acutangula germplasm could benefit the ridge gourd breeding programs to meet the demands and needs of consumers, farmers, and vegetable exporters such as increasing the yield of fruit by the fruit width but not by the fruit length to solve the problem of fruit breakage during exportation.

Nondestructive evaluation of photosynthesis by delayed luminescence in Arabidopsis in Petri dishes.

Nondestructive evaluation of photosynthesis is a valuable tool in the field and laboratory. Delayed luminescence (DL) can reflect charge recombination through the backflow of electrons. However, DL detection has not yet been adapted for whole plants in Petri dishes. To compensate for differences in DL decay between sibling Arabidopsis plants grown under the same conditions, we developed a time-sequential double measurement method. Using this method, we examined the influence of photosynthetic electron flow inhibitors, and differences in the DL decay curves were categorized by considering the initial and late phases of the decay curves, as well as their intermediate slopes. The appearance of concavity and convexity in DL curves in Arabidopsis was different from unicellular algae, suggesting complexity in the photosynthetic machinery of higher plants. This detection method should be invaluable for evaluating photosynthetic defects in higher plants under sterile conditions without interrupting plant culture.