Hybridization and Factors Influencing Seed Set in Oat

Background: Oat is mostly neglected crop for hybrid development due to its floral structure which results in high damage rate during hybridisation. Due to the cumbersome in acquiring a sufficient number of hybrids and subsequent backcrosses are difficult that lead to lack of much inheritance studies in Oats. Methods: The procedure for crossing used was almost identical to that used by oat breeders which was conducted for 2 years viz., 2019-20 and 2020-21 at Forage Station, Punjab Agriculrural University, Ludhiana. Result: The experiment was conducted to know the seed set percent in oat cultivars. Since the oat flower is fragile compared other cereals and it is easily harmed during the emasculation and pollination process. The seed set percent observed was only 12 and 10 percent in the year 2019-20 and 2020-21, respectively.

Heterosis and Heterotic Grouping among Tropical Maize Germplasm

Maize (Zea mays L.) is the most important staple cereal cultivated in sub-Saharan Africa but its productivity is considerable low due to several factors. Development and deployment of maize hybrids have been reported as one of the crucial options in achieving sustainable maize production in sub-Saharan Africa. Information on the heterotic response among available genetic materials in a breeding program is valuable before commencement of any hybrid development program. Unlike the temperate germplasm, maize tropical germplasm is characterized with wide genetic base and genetic complexities and thus, proper organization of the pools, populations, varieties and inbreds that can serve as parental materials for hybrid development through identification of a distinct heterotic groups and patterns among tropical germplasm becomes very essential. This paper reviewed past research efforts at characterizing heterotic response among tropical maize genetic materials with a view to point out merits and demerits in the methods used and future direction towards achieving sustainable hybrid cultivation and enhancing food security in the sub-region.

A Fatty Acid Anabolic Pathway in Specialized-Cells Remotely Controls Oocyte Activation in Drosophila

ABSTRACTPheromone-mediated partner recognition is crucial for maintenance of animal species. Here, we discover a metabolic link between pheromone and gamete physiology. In female genital tract, oocyte maturation is arrested at a specific meiotic-phase. Release of this arrest, called oocyte-activation, is triggered by a species-dependent signal. We show in Drosophila melanogaster that oenocytes, which produce the fatty acids (FAs) used as precursors of cuticular hydrocarbons (CHCs), including pheromones, are also essential for oocyte activation. We identified a set of FA-anabolic enzymes required within oenocytes for the synthesis of a particular FA that is not a CHC precursor but controls oocyte activation. Our study thus reveals that two tightly linked FA-anabolic pathways act in parallel, one to produce sexual pheromones, the other to initiate embryonic development. Given that pheromone-deficient Drosophila melanogaster females are highly attractive for males irrespective of their species, this oenocyte function might have evolved to prevent hybrid development.

Assessment of Genetic Diversity of Maize (Zea mays L.) Inbreds Based on Morphological Traits

The screening of forty eight maize in breds from International Maize and Wheat Improvement Center was carried out to estimate the genetic diversity and the results indicated presence of considerable diversity. The experiment was conducted in a randomized complete block design with three replication and phenotypic data were analyzed using twenty one agro-morphological traits. The forty eight maize in breds grouped into eleven clusters based on Mahalanobis D2 statistic. Among them cluster I accommodated maximum number of inbred lines (15) followed by cluster III and V (9). Existence of six solitary clusters showed larger genetic diversity. The character chlorophyll content showed highest contribution towards genetic divergence followed by anthesis to silking interval, cob girth, cob weight, hundred grain weight, number of kernels per row, days 75 per cent brown husk, plant height at 90 DAS, cob length and number of kernel rows per cob. Based upon the divergence studies suggesting crossing may be made between genotypes of cluster VIII (CAL1428) and cluster X (ZL154357, CAL1467, ZL153785, CAL1422, and ZL154346) and the hybrid in these cluster could be used as donor parents for new single cross maize hybrid development for improving yield.

Rapeseed-Mustard Breeding in India: Scenario, Achievements and Research Needs

Brassica spp., commonly known as rapeseed-mustard, plays a significant role in the Indian economy by providing edible oils, vegetables, condiments and animal feed. Globally, India holds second and third position in rapeseed-mustard area under cultivation and production, respectively. However, anthropogenically accelerated climate change thwarts yield potential of rapeseed-mustard by employing abiotic (drought, flood, temperature variation and salinity) and biotic (disease and insects) stresses. Various approaches such as molecular breeding, pre-breeding, −omics and biotechnological interventions have been used to develop varieties for improved yield and oil quality, climate resilient and resistance or tolerance to abiotic and biotic stresses. In this context, this chapter highlighted the different cytoplasmic male sterility (CMS) sources and their potential use for hybrid development. At the end, this chapter also enlisted salient achievement by the government and non-government institutes and briefly described the future perspective for improvement of rapeseed-mustard in India.