Cereal Research Communications

Abstract A weedy rye, Secale cereale subsp. segetale found in Xinjiang, China, possess strong stress tolerance, tillering capacity and many useful traits. The study aims to better understand the genetic diversity of segetale rye from China at the molecular level. The genetic diversity of 92 populations (bulked samples) and further 168 plants (individual samples from 14 populations) in the segetale rye were analyzed using 47 polymorphic EST-SSR (expressed sequence tags derived microsatellite) molecular markers. A total of 211 bands were amplified by 47 EST-SSR primers in the 92 populations. Among them, there were 190 polymorphic bands, with an average of 4.04 bands per primer and an average polymorphic ratio of 88.4%. The variation range of PIC (polymorphic information content) was 0.16–0.94 with the average 0.75, indicating abundant genetic diversity of weedy rye populations. The clustering analysis of 92 populations based on Nei's genetic distance showed that their average genetic distance was near 0.35, and 92 populations from different regions of Xinjiang were relatively scattered, generally close genetic distance between populations in the same region. Similar rule was found between individual plants in same population using clustering and principal coordinate analysis (PCoA). To 168 individual plants from 14 populations, analysis found that the average genetic differentiation among populations was 0.143, and the genetic diversity of the segetale rye populations mainly existed within populations (85.7%). Abundant genetic diversity was found within different regions and populations of segetale rye from China. The research provides a theoretical basis on the application of elite genes of segetale rye to the genetic improvement of rye and wheat.

Abstract Seed vigor is an important trait for direct-seeded rice. Many environmental and genetic factors during seed development stages influenced the seed vigor. As a result of limited source during the reproductive stage, the seeds differ in size within a seed lot due to differential seed filling. This may influence the seedling establishment and drought tolerance ability of the genotype which, however, is less studied. In this regard, the objective of this study was to assess the influence of seed size on seed germination, vigor and drought tolerance in rice. Seeds of six rice genotypes were separated into large and small size. Seed length, width and weight showed significant variation between large and small groups within the genotype. The seedling vigor was higher in larger seeds in all the genotypes. Seed reserves content was also higher in large seeds than in small seeds except for two genotypes. In limited nutrient supply conditions, root length was significantly increased in larger seed seedlings. However, under sufficient nutrient supply, shoot length was significantly increased than root length in larger seed seedlings. Under drought conditions, seedlings from larger seeds showed lower superoxide accumulation and membrane damage indicating higher drought tolerance. Higher seed vigor through better root growth and activation of drought tolerance mechanisms was found to be the key factor for survival during seedling establishment stage.

Abstract Pearl millet is one of the major food crops, particularly grown in arid and semi-arid regions of the world. This study aimed to determine correlation and path analysis for morpho-phenological and yield contributing traits along with grain micronutrients (Fe and Zn) in 184 advanced breeding lines and four checks viz., ICMV-221 (NC), ICTP-8203 (NC), VPMV-9 (LC) and Dhanashakti (NC), were assessed using Augmented Block Design during kharif 2021–22 at two locations viz., Regional Agricultural Research Station, Vijayapur and Agricultural Research Station, Mudhol. Analysis of Variance indicated the existence of sufficient variation in the material studied. The traits like 1000 grain weight, dry fodder yield, plant height, panicle girth and panicle length had significant and positive phenotypic correlation with grain yield. There was a highly significant and high positive correlation between the Fe and Zn content. These results would imply that simultaneous selection for high levels of both Fe and Zn content is possible. The path analysis indicated that the traits viz., 1000 grain weight, dry fodder yield, panicle girth and plant height had high and positive direct effects on grain yield. This indicates that grain yield can be improved through direct selection by these characters. Strong association of these traits revealed that the selection based on these traits would ultimately improve the yield.