S. A. Rao

Bio: S. A. Rao is an academic researcher from Assiniboine Community College. The author has contributed to research in topics: Genetic divergence & Cultivar. The author has an hindex of 2, co-authored 4 publications receiving 18 citations.

Genetic diversity in Indian sub-continental landrace cultivars of the genus Triticum L.

Abstract: Narrowing genetic diversity is a limiting factor in wheat breeding. Popularity of semi dwarf cultivars, developed after green revolution, has resulted in genetic erosion as they replaced indigenous cultivars derived from landraces. These old cultivars have a wealth of useful genes that can be incorporated in the modern cultivars to improve their tolerance level against biotic and abiotic stresses. Genetic analysis of these indigenous and advanced cultivars by the SSR markers has shown greater diversity in this valuable Indian sub-continental germplasm and grouped them into seven units. The Triticum durum lines T2 and T3 were placed in group A, whereas their counterpart T1 was quite distinct. Of the selections, T4 to T9 that was clustered in Group B, T4 to T7 were of Triticum sphaerococcum , whereas the other two were of Triticum aestivum type. T. aestivum cultivar C-248 also appeared to be distinct and could not be grouped with any other cultivar. Based on genetic divergence, therefore, T1 can be used for enhancing diversity in T. durum and C-248 in T. aestivum . Keywords: Triticum , germplasm, simple sequence repeats, genetic diversity

Differential response of plant species to greenhouse microclimate created by design technology and ambient conditions

Abstract: Food insecurity amongst First Nation populations living on reserves across Canada is purported to be about 27% of the national average. However, crop production is limited by factors such as climate and soil conditions. A 2-yr study was carried out to assess production of collard (Brassica oleracea L. var. acephala DC. ‘Champion’), carrot (Daucus carota L. ‘Adelaide’), and tomato (Lycopersicon esculentum Mill. ‘Beefsteak’) in three separate greenhouses with contrasting design technologies. The greenhouses were categorized as (i) high technology (HTG), (ii) medium technology (MTG), and (iii) low technology (LTG) greenhouses. The MTG and LTG were basic facilities but the MTG had in-floor heating. The HTG was fully equipped with climate control systems. Mean monthly air temperature was stable at 23 °C ± 1 °C in the HTG but fluctuated in the MTG and LTG. Air temperature and water loss were highest in the MTG. Vapour pressure deficit and daily light integral followed the trends LTG > MTG > HTG > ambient and am...

Wintering Index and Yield Traits for Early, Mid, and Late Season Strawberry for Colder Climates

Abstract: In temperate climatic regions where severe winter conditions persist, the winter hardiness and fruit yield of strawberry cultivars vary greatly in perennial production systems. A 4-year study was c...

Population structure and genetic diversity among Indian wheat varieties using microsatellite (SSR) markers

Abstract: Platform for improvement of crop plants is largely setup by the genetic variability studies. The current work was performed to assess the status of genetic diversity among 319 Indian wheat varieties so that they can be used effectively for future breeding practices. Out of 30 markers applied, 50 polymorphic fragments generated from16 polymorphic primers were selected for diversity studies. Jaccob's similarity model and Bayesian analysis were performed using software package DARwin 5.0 and STRUCTURE 2.3.3 respectively. Grouping obtained from both the analysis were found to be consistent and was helpful in analyzing the distribution of genetic variability across different centres of wheat research in India. The total genetic diversity for all groups (Ht) was 0.38888 and within groups (Hs) was 0.3130 indicating less genetic variability among sub-populations (Gst=0.19). Gene flow (Nm) was also found to be relatively high with a value of 2.0654. Genetic variability parameters computed using POPGENE 1.32 (81%) and AMOVA (78.5%) revealed that the genetic diversity was mainly contained within the populations. This study can complement the breeding programs for identification of parental combinations effectively to maintain maximum genetic variability in progenies.

From RFLP to DArT: molecular tools for wheat ( Triticum spp.) diversity analysis

Abstract: Wheat (Triticum spp.) is a universally lucrative agricultural crop. An increase in wheat production has been shown through selection by the farmers which can increase the grain profitability. The determination of genetic associations among domestic cultivars is facilitated by molecular markers. Data on genetic polymorphism is valuable for the germplasm association and regarding the developing management strategies. The information would be supportive for potential genome mapping programs and for the relevance of intellectual property rights of wheat breeders. Present review is an effort for providing support information to wheat breeders to develop varieties with varied genetic environment to attain continuity in large-scale wheat production. In this review, we have tried to provide a collective depiction of relevant information about the usage of some commonly used markers in wheat. It may help researchers to find out the frequentness and application of different markers and compare their results. The manuscript may serve as a platform helping the intellectuals for the selection and modification of their marker system in wheat diversity analysis. The heart of this review is the emphasis on the performance of various molecular genetic markers in diversity studies in relation to definite approaches that are in practice since several years allied with the multifaceted wheat molecular breeding and its polyploid nature.

How diverse a farmer-managed wheat landrace can be?

Abstract: Phenotypic variation in phenological, quantitative and qualitative traits was assessed in geographically-isolated, farmer-managed wheat landrace populations grown under subsistence farming conditions. Several multivariate, genetic diversity and structural equation modeling procedures were used to build a comprehensive structure of the landrace and to (1) identify and construct multivariate distances between components of the landrace, (2) identify plant- and seed-related traits contributing to its composition, (3) build principal components that can account for maximum variation, (4) quantify variance components accounted for by major seed qualitative traits, (5) partition total diversity and estimate levels of population differentiation, (6) build and validate a predictive model of landrace population-trait association, (7) identify traits affecting spikelet fertility as a critical component of grain yield under the prevailing hot conditions in Oman, and (8) construct and interpret structural equation models to estimate the direct and indirect effects of quantitative and qualitative traits on grain yield per plant for each landrace population. The results will be discussed within the context of on-farm conservation and sustainable utilization of endangered wheat landrace populations under subsistence farming and to illustrate the use of advanced multivariate statistical methods in assessing phenotypic variation in subdivided landrace populations.

Response of Kale to Single-Dose Application of K Humate, Dry Vermicasts, and Volcanic Minerals

Abstract: Worldwide consumers are concerned about potential residue and persistence of harmful chemicals in the environment and on foods, especially leafy vegetables like kale, Brassica oleracea L. var. acephala (DC.) Alef. A greenhouse pot experiment was conducted to determine whether kale, cv. Ripbor, responded to different natural sources of growing medium amendments: 47.5 g K humate/pot; 50 g dry vermicastst/pot; or 100 g volcanic minerals/pot. Each of the amendments were individually added to 1 kg Pro-mix BX/pot with the Pro-mix BX alone as the control. Plant growth rate grown in dry vermicasts was highest. The fresh weight was higher due to volcanic minerals than for the control and values for K humate and dry vermicasts were similar to the control and volcanic minerals. The dry vermicasts reduced leaf and stem mass densities compared to other treatments. Leaf dry matter content was increased by approximately 29% in the K humate, the volcanic minerals, and the control compared to the dry vermicasts. S...