The germination process is one of the most sensitive stages in the early development of plants. The behavior and the responses of the plants in agronomic, biological and ecophysiological studies can be inferred through this process. However, the calculation of the germination variables is laborious. In this sense, the GerminaR package for the statistical software application R, which includes an interactive web application "GerminaQuant for R" for users without programming knowledge is presented. These tools should contribute greatly to improve analyses in germination studies.
Maintaining a viable seed bank throughout the germination season is considered very important for plant recruitment in desert environments, where environmental conditions are unpredictable. Seeds from fully matured Seidlitzia rosmarinus Bunge ex Boiss and Halothamnus iraqensis Botsch. were collected in December 2016, then April, June, and September 2017 from both soil-surface and aerial seed banks. Both of the species were selected mainly by their capacity to rehabilitate saline coastal sites. Germination was analyzed under two photoperiods (0 or 12 h light per day), with winged or dewinged perianths. Seidlitzia rosmarinus had a shorter seasonal range in comparison with H. iraqensis (6 and 9 months, respectively), and the presence of a winged perianth reduced the germination rate of both species. A permanent winged perianth significantly inhibited the germination rate in both species. In the absence of perianth, the germination registered in December 2016 was mostly 100%, but declined to around 20% in September 2017. Seeds are thus more likely to germinate after scarification from wind mobilization, and do not require burial. Our results show that seeds of both the aerial and soil banks are transitory, and viable only during the winter months. Taken together, the combination of aerial and soil seed banks has greatly facilitated germination asynchrony in their environmentally unpredictable desert habitat.
Quinoa (Chenopodium quinoa Willd.) is an ancient food crop that originated in the Andes. It has good nutritional properties that increasingly attract interest around the world and it is considered as a future crop for food security and climate change adaptation. Currently, there is a great need to develop new quinoa varieties with higher yield, tolerance to biotic and abiotic stresses, and adaptation to new growing areas. Despite the existence of breeding programs, quantitative genetic parameters that are relevant for selection gain have hardly been investigated for quinoa. We estimated these parameters for important agronomic traits in six segregating populations of 96 lines each, derived from crosses of popular traditional Peruvian quinoa varieties. The traits were evaluated in trials at several locations in the Peruvian highlands over 3 years. Maturity was the best phenological stage for trait evaluation because at this stage we obtained high estimates of heritability and high correlation of panicle trait indices with grain yield. Based on these traits, we selected the 18 best lines and characterized them in additional field trials for the same traits. Three lines (HUA × KAN53, SAL × NCO46 and SAL × PAN171) combined advantageous traits of their parents and showed lower plant height, earlier maturity and higher yield. Our work shows that the estimation of variance and variance components in the amphidiploid crop quinoa provides useful information for the design of breeding programs and the selection of improved genotypes for cultivation in the Peruvian highlands.
Los problemas futuros de producción de arroz están relacionados con el calentamiento global y la escasez de agua como consecuencia del cambio climático. Para una producción eficiente y sustentable en el cultivo de arroz, deben modificarse el manejo de riego por inundación y las altas aplicaciones de nitrógeno. Entre las principales recomendaciones se incluye la incorporación del fertilizante nitrogenado en las fases críticas del cultivo y el uso de siembra directa en suelo seco, en lugar del método de trasplante. El presente manuscrito reúne también recomendaciones para mejorar la eficiencia agronómica y el uso del nitrógeno en el cultivo de arroz. Las recomendaciones técnicas mencionadas deben implementarse a fin de mejorar la productividad del cultivo y fortalecer la seguridad alimentaria.
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