Maize is the staple food crop in hilly areas of Nepal. Drought stress is one of the most important crop growth limiting factors leading to lower crop productivity in these areas. Maize seedlings are susceptible to drought stress. Nine lines (Arun-2, NML-1, Rampur Composite, RL-100, RL-105, Rl-106, RL-197, RML-18 and RML-8) of maize obtained from National Maize Research Program, Rampur, Chitwan, Nepal to study their tolerance to drought stress. An experiment was designed to study their drought tolerance by subjecting to four levels of osmotic potential (0,-5,-10 and-15 bar) induced by polyethylene glycol (PEG) 6000 in two factor completely randomized design with three replication at Biotechnology Division, National Agricultural Research Institute, Khumaltar, Lalitpur, Nepal. Effects of different levels of PEG 6000 were found significant on all traits studied viz. Germination rate (%), Speed of germination, Root length, Shoot length, Root Shoot ratio, Seedling length, Seedling fresh weight, Seedling dry weight and Vigor index. Line Arun-2 was recorded as best performer followed by Rampur Composite and RL-105 for all the traits analyzed. Lines RL-100, RL-106, RL-197, RML-18 and RML-8 showed poor performance under the same levels of PEG induced drought stress. Furthermore, the results also showed that maize manifests better genetic expression such as drought tolerance under severe moisture stress conditions in soil. Therefore, Lines Arun-2, Rampur Composite and RL-105 are suggested for varietal improvement program for drought stress conditions.

The present investigation was undertaken with the objective to develop high yielding, fine grain rice varieties possessing broad spectrum durable resistance by transferring bacterial leaf blight (BLB) resistant genes viz., xa13 and Xa21 from B95-1. A popular high yielding and fine grain rice variety, MTU1010 (Cottondora Sannalu), susceptible to BLB and B95-1 carrying resistant genes for BLB (xa13 & Xa21 genes) was selected as the parent for crossing. B95-1 was verified for the presence of target genes by using gene linked primers viz., xa13 promotor and pTA 248. These primers were also used to study polymorphism between resistant (B95-1) and susceptible (MTU1010) parents. The cross viz., MTU1010 x B95-1 was affected during Rabi, 2010 and F1 progenies were confirmed during Kharif, 2011. The F1 plants confirmed as true hybrids for both the genes were advanced to F2 generation and foreground selection was done using gene linked markers. Genetic analysis in F2 populations confirmed that the genes (xa13 & Xa21) governing BLB resistance followed Mendelian inheritance. The phenotypic data analysis revealed that the plants carrying two resistance gene combinations (xa13xa13 Xa21Xa21, xa13xa13Xa21xa21) showed BLB resistance (0-2 scale), while the gene combinations viz., Xa13Xa13Xa21Xa21, Xa13Xa13Xa21xa21, and Xa13xa13Xa21Xa21, Xa13xa13Xa21xa21 showed BLB resistance (0.5-3.0).DOI: http://dx.doi.org/10.3126/ijasbt.v2i3.10570 Int J Appl Sci Biotechnol, Vol. 2(3): 229-237

The AP2/ERF superfamily is one of the largest groups of transcription factors (TFs) in plants, which plays important roles in regulating plant growth and development under heat stress. A complete genome-wide identification, characterization, and expression analysis of AP2/ERF superfamily genes focusing on heat stress response were conducted in bread wheat. This study identified 630 putative AP2/ERF superfamily TF genes in wheat, with 517 genes containing well-defined AP2-protein domains. They were classified into five sub-families, according to domain content, conserved motif, and gene structure. The unique genes identified in this study were 112 TaERF genes, 77 TaDREB genes, four TaAP2 genes, and one TaRAV gene. The chromosomal distribution analysis showed the unequal distribution of TaAP2/ERF genes in 21 wheat chromosomes, with 127 pairs of segmental duplications and one pair of tandem duplication, highly concentrated in TaERF and TaDREB sub-families. The qRT-PCR validation of differentially expressed genes (DEGs) in contrasting wheat genotypes under heat stress conditions revealed that significant DEGs in tolerant and susceptible genotypes could unequivocally differentiate tolerant and susceptible wheat genotypes. This study provides useful information on TaAP2/ERF superfamily genes and reveals candidate genes in response to heat stress, which forms a foundation for heat tolerance breeding in wheat.

Dactylorhiza hatagirea (D. don), commonly known as ‘Panchaule’ in Nepal, is a terrestrial orchid found in temperate to the alpine region. It is valued for its ornamental and medicinal use. It is collected haphazardly from nature due to high economic demand. However, its propagation is limited in nature due to its non-endospermous seeds requiring mycorhizal fungal association for germination. This limitation is leading to the extinction of this orchid from nature and has been enlisted as an endangered and threatened species. Its collection and trade are restricted but have been prioritized for research, conservation, and agro-technology development. As very few research has been reported in D. hatagirea, found in Nepal, intensive research, propagation, reintroducing, and commercial cultivation will help control the rhizome collection from nature and meet the economic demand. It will help in the identification and conservation of our local germplasm through its diversity study at the molecular and revenue generation through commercial cultivation under artificial conditions. In this review paper, we discuss the limited research and developments conducted in Dactylorhiza at various levels and ways forward for its research, conservation, and utilization. As the plant is valued for its biochemical constituents, modern biotechnological tools such as transcriptomics and metabolomics can be best utilized to explore the opportunities and increase its production and reintroduction through mass propagation for better commercialization and conservation.