Comparative studies of reproductive biology, seed morphology and anatomy of new salt tolerant accessions of Quinoa (Chenopodium quinoa Willd.) introduced in Kur-Araz lowland (Azerbaijan)

Abstract

Investigated salt tolerant top-ranking accessions of Quinoa introduced on drought prone and salt affected soils with higher clay contents, water holding capacity, evapotranspiration and shallow water in Kur-Araz (Azerbaijan) undergone all ontogenetic reproductive (pollen grain productivity, embryo and fruit developmental stages) and produce viable seeds. The floral initiation stage varies between 66-77 days depending on genotype, plant height, days to flowering and to seed maturity, and dry weight biomass (p > 0.05). The interaction effect of location and genotypes was significant for days to flowering and seed maturity and dry weight, though not for plant height and seed yield. Three earlymiddle and late-flowering, and thus early-middle and late seed maturation clusters of quinoas was described. Quinoa is predominantly self-pollinating species, but pollination inside the inflorescence by means of wind (anemophilous) or with support of small insects (entomophilous) occurs. There was no significant difference in the fruit and seed morphology among investigated accessions of quinoa cultivated under new environments. Fruits of quinoa are simple, dry, indehiscent, achene, monosperm with white pericarp in the mature state and remainans of perigonium, albuminous white or yellowish seed 1.8-2.5 mm in diameter. In quinoa seeds the pericarp is very thin; as a result, the achene is also referred to as utricle. Viable seed contains a peripheral, curved embryo surrounding by perisperm and pericarp. Pronounced micropylar endosperm (a non-embryonic tissue) of one or two cell layers thick forms a cone surrounds the root apical meristem of the embryo. Anatomy of quinoa micropylar endosperm revealed similarities in structure with coleorhiza cells in cereals. Both tissues serve as store reserve and play vital role by protecting the root apical meristem in the quiescent seed and control dormancy during germination. Further investigation of micropylar cellular tissue of quinoa, where stores lipids, proteins and minerals should be considered to select better adapted genotypes with high seed yields and nutritional quality combined with salt-and drought-tolerance. Freshly collected quinoa seeds have endogenous physiological type of dormancy. All investigated quinoa accessions, except Quinoa-Q2 showed high germination rate (78-85%) through 16 hours at room temperature (24-25 ºC). Identification of desirable genotypes needs to be followed by work on optimization of cultural practices and seed storage to maximize productivity under the drought-prone and salt affected of Kur-Araz farming areas. Early seed sowing in the field is required, thus early flowering and seed maturation occurs long before heat summer season starts.