Agro-Morphological, Yield and Quality Traits and Interrelationship with Yield Stability in Quinoa (Chenopodium quinoa Willd.) Genotypes under Saline Marginal Environment.

Quinoa (Chenopodium quinoa Willd.) is a halophytic crop that shows resistance to multiple abiotic stresses, including salinity. In this study we investigated the salinity tolerance mechanisms of six contrasting quinoa cultivars belonging to the coastal region of Chile using agro-physiological parameters (plant height (PH), number of branches/plant (BN), number of panicles/plant (PN), panicle length (PL), biochemical traits (leaf C%, leaf N%, grain protein contents); harvest index and yield (seed yield and plant dry biomass (PDM) under three salinity levels (0, 10, and 20 d Sm-1 NaCl). The yield stability was evaluated through comparision of seed yield characteristics [(static environmental variance (S2) and dynamic Wricke's ecovalence (W2)]. Results showed that significant variations existed in agro-morphological and yield attributes. With increasing salinity levels, yield contributing parameters (number of panicles and panicle length) decreased. Salt stress reduced the leaf carbon and nitrogen contents. Genotypes Q21, and AMES13761 showed higher seed yield (2.30 t ha-1), more productivity and stability at various salinities as compared to the other genotypes. Salinity reduced seed yield to 44.48% and 60% at lower (10 dS m-1) and higher salinity (20 dS m-1), respectively. Grain protein content was highest in NSL106398 and lowest in Q29 when treated with saline water. Seed yield was positively correlated with PH, TB, HI, and C%. Significant and negative correlations were observed between N%, protein contents and seed yield. PH showed significant positive correlation with APL, HI, C% and C:N ratio. HI displayed positive correlations with C%, N% and protein content., All measured plant traits, except for C:N ratio, responded to salt in a genotype-specific way. Our results indicate that the genotypes (Q21 and AMES13761) proved their suitability under sandy desert soils of Dubai, UAE as they exhibited higher seed yield while NSL106398 showed an higher seed protein content. The present research highlights the need to preserve quinoa biodiversity for a better seedling establishment, survival and stable yield in the sandy desertic UAE environment.

Effect of salinity stress on phenotypic plasticity, yield stability, and signature of stable isotopes of carbon and nitrogen in safflower.

Salinity is one of the major factors contributing in land degradation, disturbance of soil biology, a structure that leads to unproductive land with low crop yield potential especially in arid and semiarid regions of the world. Appropriate crops with sufficient stress tolerance capacity and non-conventional water resources should have to be managed in a sustainable way to bring these marginal lands under cultivation for future food security. The goal of the present study was to evaluate salinity tolerant potential (0, 7, and 14 dS m-1) of six safflower genotypes that can be adapted to the hyper arid climate of UAE and its marginal soil. Several agro-morphological and physiological traits such as plant dry biomass (PDM), number of branches (BN), number of capitula (CN), seed yield (SY), stable isotope composition of nitrogen (δ15N) and carbon (δ13C), intercellular CO2 concentration from inside to ambient air (Ci/Ca), intrinsic water use efficiency (iWUE), carbon (C%) and nitrogen (N %), and harvest index (HI) were evaluated as indicative of the functional performance of safflower genotypes under salt stress. Results indicated that salinity significantly affected the seed yield at all levels and varied significantly among genotypes. The BN, PDM, CN, and δ13C attributes showed clear differentiation between tolerant and susceptible genotypes. The δ13C results indicate that the tolerant genotypes suffer less from stress, may be due to better rooting. Tolerant genotypes showed lower iWUE values but possess higher yield. Safflower genotypes (PI248836 and PI167390) proved to be salt tolerant, stable, and higher seed and biomass yielder. There was no G × E interaction but the genotypes that produce higher yield under control were still best even under salt stress conditions. Although salinity reduced crop yield, some tolerant genotypes demonstrate adaptation and good yield potential under saline marginal environment.

Genotypic differences in agro-physiological, biochemical and isotopic responses to salinity stress in quinoa (Chenopodium quinoa Willd.) plants: Prospects for salinity tolerance and yield stability.

Quinoa is an important nutritive crop that can play a strategic role in the development of marginal and degraded lands. Genotypic variations in carbon isotope composition (δ13C), carbon isotope discrimination (Δ13C), ratio of intercellular to atmospheric CO2 concentration (Ci/Ca), intrinsic water use efficiency (iWUE), seed yield and grain protein contents were analyzed in 6 quinoa cultivars grown in the field under saline conditions (0, 10, 20 dS m-1). Significant variations occurred in dry biomass, seed yield, plant height, number of branches, number of panicles, panicle weight, harvest index, N and C content. Some genotypes produced yields with values significantly higher than 2.04 t ha-1 (Q12), with an average increased to 2.58 t ha-1 (AMES22157). The present study indicates a large variation in Δ13C for salinity treatments (3.43‰) and small magnitude of variations among genotypes (0.95‰). Results showed that Δ might be used as an important index for screening, and selection of the salt tolerant quinoa genotypes with high iWUE. Quinoa genotypes differs in foliar 13C and 15N isotope composition, which reflected complex interactions of salinity and plant carbon and nitrogen metabolisms. Grain protein contents were found higher in Q19 and Q31 and lowest in Q26. The study demonstrates that AMES22157 and Q12, were salt tolerant and high yielder while the AMES22157 was more productive. This study provides a reliable measure of morpho-physiological, biochemical and isotopic responses of quinoa cultivars to salinity in hyper arid UAE climate and it may be valuable in the future breeding programs. The development of genotypes having both higher water use efficiency and yield potential would be a very useful contribution for producers in the dry region of Arabian Peninsula.

Genotypic Variation for Salinity Tolerance in Cenchrus ciliaris L.

Scarcity of irrigation water and increasing soil salinization has threatened the sustainability of forage production in arid and semi-arid region around the globe. Introduction of salt-tolerant perennial species is a promising alternative to overcome forage deficit to meet future livestock needs in salt-affected areas. This study presents the results of a salinity tolerance screening trial which was carried out in plastic pots buried in the open field for 160 buffelgrass (Cenchrus ciliaris L.) accessions for three consecutive years (2003-2005). The plastic pots were filled with sand, organic, and peat moss mix and were irrigated with four different quality water (EC 0, 10, 15, and 20 dS m(-1)). The results indicate that the average annual dry weights (DW) were in the range from 122.5 to 148.9 g/pot in control; 96.4-133.8 g/pot at 10 dS m(-1); 65.6-80.4 g/pot at 15 dS m(-1), and 55.4-65.6 g/pot at 20 dS m(-1). The highest DW (148.9 g/pot) was found with accession 49 and the lowest with accession 23. Principle component analysis shows that PC-1 contributed 81.8% of the total variability, while PC-2 depicted 11.7% of the total variation among C. ciliaris accessions for DW. Hierarchical cluster analysis revealed that a number of accessions collected from diverse regions could be grouped into a single cluster. Accessions 3, 133, 159, 30, 23, 142, 141, 95, 49, 129, 124, and 127 were stable, salt tolerant, and produced good dry biomass yield. These accessions demonstrate sufficient salinity tolerance potential for promotion in marginal lands to enhance farm productivity and reduce rural poverty.