Potting media are an integral part of potted plants production system, formulated by a mixture of various raw materials to act as a substrate for plant support and source of nutrition. There is a wide range of potting media available, which are used for quality production of high-value plants worldwide. In this study, quality assessment of Dracaena plants grown in different potting media like: mushroom compost, peat, sand, farmyard manure, coconut coir, and leaf compost in different combinations were carried out. A mixture of sand, mushroom compost, coconut coir, and peat proved to be the best, by promoting root and shoot growth, leaf area, fresh and dry weights of root and shoot, and also improved overall quality of the plant. Media containing garden soil alone or a mixture of sand and leaf compost produced the lowest quality of plants with considerable reduction in most of the growth parameters. Anatomical parameters showed weak relation to media composition as compared to other morphological features. The best medium was made with sand, mushroom compost, coconut coir, peat, that produced plants with thick epidermis and larger pith cells, but thin endodermis and smaller metaxylem vessels in their roots. As moisture availability was sufficient enough in this medium combination, the development of water storing tissue may not contribute significantly. However, epidermis can play a decisive role in protecting roots from external environmental hazards.

Plant breeding requires genetic diversity of useful traits for crop improvement. EMS-induced mutation is practiced to generate mutations at loci regulating economically important traits and/or to knock out the genes to elucidate their functions. The present study was aimed to induce mutations in a Korean local land race Capsicum annuum ‘Yuwol-cho’. This accession is pungent and also has advantage to mature early. A total of about 1,500 M2 families were screened and three non-pungent mutants were identified and crossed with wild type ‘Yuwol-cho’. After phenotyping of F2 population for pungency, MutMap approach will be used to identify the genes controlling the pungency in mutants. In addition to this, another C. annuum accession “Micro-Pep” was used to develop a mutant population. Micro-Pep is a small, pungent pepper generally used as ornamental purpose. Having compact growth habit, and small size, it has advantage to handle and utilize easily in mutation study and molecular research. On the basis of preliminary experiment 1.3% of mutagen was used for treatment of pepper seeds and 30% less germination percentage was observed in EMS treated seeds in comparison to control seeds. A total of 4,674 M1 plants are grown under greenhouse condition and M2 population will be studied for characterization of phenotypic variation including fruit color and pungency. Newly constructed mutant populations will be valuable assets for identification of functional genes and molecular breeding of pepper.

Phytophthora capsici an Oomycete pathogen is a major challenge to the pepper (Capsicum spp.) production around the world. Control measures are proved ineffective, so breeding resistant cultivars are the most promising strategy against the pathogen. Resistance against P. capsici is governed by quantitative trait loci (QTL). According to previous studies on QTL detection, the QTL on pepper chromosome 5 is a major contributor to resistance. In this study, to exploit the involvement of this QTL and identify its contributing genes, the F2 population derived from a cross between ECW30R and CM334 was inoculated with a medium virulence P. capsici strain JHAI1-7 zoospores at the 6-8 leaf stage. Composite interval mapping revealed two major QTLs; QTL5-1 from 7 days post inoculation (dpi) and QTL5-2 from 16 dpi on chromosome 5. To characterize and detect interactions of the two QTLs, near isogenic lines (NIL) were constructed by crossing Tean and recombinant inbred line (RIL) derived from a cross between YCM334 and Tean. RILs were screened with P. capsici strain MY-1 and resistant lines were selected. Among the resistance RILs most closely related to Tean were selected using AFLP and SSR genotyping data. These RILs were named as YT39-2 and YT143-2. To develop more advanced NILs, two rounds of marker-assisted backcrossing were done using a high-throughput SNP genotyping system (EPI Fluidigm, USA). Among the NILs derived from YT39-2, YT39-2-64 contains only QTL5-1 whereas YT39-2-61 and YT39-2-69 were identified to have both QTLs. On the other hand, YT143-2-55-7 with the highest Tean genetic background contains QTL5-1 only. In the next step, the 3 different NILs having QTL5-1, QTL5-2 individually and both QTLs will be identified. Furthermore, phenotyping and fine mapping will be done for the analysis of individual and interaction effects of QTLs.