Evaluation of the Ph‐3 gene‐specific marker developed for marker‐assisted selection of late blight‐resistant tomato

Abstract

Late blight caused by Phytophthora infestans is one of the most destructive diseases of tomato (Solanum lycopersicum L.) that mainly occurs in cool and wet environments. With the spread of the A2 mating type and new clonal lineages, fewer fungicides provide effective control of the disease, which has increased its worldwide threat. Host resistance could contribute significantly to sustainable disease control. Ph-3 is a race-specific late blight resistance gene commonly used in commercial tomato breeding. Availability of precise and easy to use gene-based markers would facilitate selection. In this study, a Ph-3 on-gene cleaved amplified polymorphic sequence (CAPS) marker, Ph3.gsm/HincII, was developed based on the published gene sequence of Ph-3. The effectiveness of the marker was evaluated along with other published Ph-3 markers using an F 9 recombinant inbred line (RIL) population derived from NC 23E-2 (93) 9 L3708. Markers Ph3.gsm/HincII and TG328/BstNI accurately genotyped the RIL population for Ph-3. In addition, Ph3.gsm/HincII was able to differentiate variable susceptible alleles. This reliable codominant DNA marker would be very useful in marker-assisted selection, particularly for resistance gene pyramiding.

Genetic diversity of the breeding collection of tomato varieties in Kazakhstan assessed using SSR, SCAR and CAPS markers

“…Both markers are dominant SCAR markers linked with the corresponding resistance loci introduced to tomatoes from Solanum pimpinellifolium ( Arens et al, 2010 ). Two codominant markers, Ph3-gsm and TG328, have been linked with the Ph-3 locus conferring resistance to P. infestans ( Robbins et al, 2010 ; Wang et al, 2016 ). Two local cultivars, ‘Meruert’ and ‘Leader’, had the resistant allele of Ph3-gsm; the only specimen with the resistant variant of TG328 was the Russian cultivar ‘Korolek [Kinglet]’.…”

“…Due to the high genetic variability of this pathogen, the known resistance loci in tomato have only limited protective effect specific to particular Phytophthora isolates ( Nowicki et al, 2012 ). The CAPS markers used here, TG328 and Ph3-gsm, are linked with the Ph-3 resistance locus ( Robbins et al, 2010 ; Wang et al, 2016 ), which confers partial resistance to a range of Phytophthora isolates and is widely used in breeding practices ( Jung et al, 2015 ).…”

Trait discovery and editing in tomato

“…The acylsugars metabolism in trichomes and their role in insect defense were also deciphered and the role of an isopropylmalate synthase and of acyltransferases underlined (Ning et al ., ; Schilmiller et al ., ). Screening for the discovery of markers for new resistance genes has also continued with a higher efficiency thanks to the availability of reference genome sequences (Bao et al ., ; Haggard et al ., ; Kim et al ., , , ; Wang et al ., ; Hameed et al ., ).…”

FEATURES OF THE PRIMARY STRUCTURE OF THE Ph-3 GENE, REVEALED BY DEVELOPMENT OF A NEW GENE-BASED MARKER OF LATE BLIGHT RESISTANCE IN TOMATO

“…Также предпринимаются попытки маркировать ген Ph-3 для более эффективного переноса в представляющий селекционный интерес материал с помощью маркер-опосредованной селекции (marker assistant selection, MAS) и пирамидирования с другими генами устойчивости к фитофторозу. На сегодняшний день известно несколько ДНК-маркеров, так или иначе ассоциированных с этим геном, в том числе три SCAR (sequence characterised amplified region) маркера (18)(19)(20) и один CAPS (cleaved amplified polymorphic sequences) маркер (21). Однако эти маркеры обладают рядом недостатков.…”