AVRDC

CORNUCOPIA6SeminarsSheue­chin “Jin” Shieh, Assistant Specialist, Pepper Breeding gave a talkon inheritance of heat tolerance in sweet peppers to colleagues atheadquarters on 4 October 2012. Temperature is the most crucial factoraffecting sweet pepper production; heat stress can inhibit root and shootgrowth, cause flowers to drop, reduce pollen viability, and reduce fruit weight.Jin is researching inheritance of heat tolerance traits to develop improvedscreening methods for heat stress and to design breeding strategies for sweetpeppers that can take the heat. Three additive genes appear to be involved foryield traits under heat stress; by combining heat tolerant components (e.g.root growth, pollen viability) from different lines, breeders may be able todevelop improved heat-tolerant sweet pepper.Shin-Jiun Vicky Cherng, Assistant Specialist, Bulb Alliums, discussedpropagation techniques for virus-free garlic bulbs in a seminar on 11 October2012. Viruses affect bulb quality and decrease yield; they also accumulate inplanting material. Strategies to produce healthy planting material includeselection of disease-free bulbs for propagation and tissue culture. Multiplyinggarlic via tissue culture of florets from emerging 1 cm-long scapes couldgenerate healthy garlic bulbils within one year, much quicker than shoot-tipculture.Roland Schaefleitner, Head, Molecular Genetics, gave a presentation on“Molecular markers: from SSRs to SNPs” on 18 October 2012 to headquarterscolleagues. Simple sequence repeats (SSRs) and single nucleotidepolymorphisms (SNPs) are DNA fragments found at certain locations in agenome. Roland explained how these landmarks are used to produce thegenetic maps plant breeders consult to associate phenotype with genotype,and to assess the interaction of genes governing traits such as yield or fruitsize, or those conferring heat or drought tolerance. Roland is currentlyworking on resistance gene mapping for tomato, pepper and mungbean,mutant screening in tomato, and embryo rescue after wide crosses.WelcomePatcharaporn (Joom) Suwor,Graduate Student from theDepartment of Plant Science andAgricultural Resources, Khon KaenUniversity, Thailand, will extend herinternship at AVRDC headquarters foranother six months, to 31 March 2013.Funded by the Royal Golden Jubilee Ph.D. Scholarship,Joom will continue her work on molecular markers foranthracnose resistance in pepper for her thesis entitled“Combining anthracnose resistant genes into hot peppervarieties” under the supervision of Sanjeet Kumar,Scientist – Pepper Breeding.Ayumu Onozato, ResearchIntern / Tomato Breeding, fromKAGOME Co., Ltd., ResearchInstitute, Japan, arrived at AVRDCheadquarters on 10 October 2012 fora two-month internship to study fieldand laboratory methods for diseaseresistance screening in tomato under the supervision ofPeter Hanson, Plant Breeder.