Evolution of the response of segregating populations of plums and the association with microsatellite markers of leaf scald

Abstract

-The evolution of leaf scald (Xylella fastidiosa) resistance was evaluated in individuals of seven plum segregating populations, consisted of seedling progenies originating from crosses involving nine plum cultivars, with varied levels of resistance. Plants were submitted to artificial inoculation in 2001 and evaluated annually from 2002 to 2007 for the evolution of leaf scald symptoms. All populations showed an evolution of symptom severity during the evaluated period. The population Amarelinha x Carazinho was the most resistant while populations Chatard x Santa Rosa and Chatard x Simka were the most susceptible ones. The populations Chatard x Harry Pickstone and Chatard x Angeleno exhibited an intermediate behavior. The analysis of genetic segregation of microsatellite markers and disease resistance curves in different populations indicated that inheritance to leaf scald resistance is polygenic and predominantly recessive, with an eventual presence of major QTLs in susceptible parents.

DNA fingerprinting of Japanese plum (Prunus salicina) cultivars based on microsatellite markers

“…Currently, some of these cultivars are commercially cultivated in south Brazil, such as Fortune and Laetitia cultivars. Other cultivars represent the genetic pool for the Japanese plum breeding, such as Chatard, Piamontesa and Carazinho, which are highly resistant to leaf scald (Dalbó et al 2010). The Japanese plum collection is located at Epagri -Videira Experimental Station (Videira, SC, Brazil), lat 27° 00' 30" S, long 51° 09' 06" W, and alt 800 m asl.…”

Diseases Caused by Xylella fastidiosa in Prunus Genus: An Overview of the Research on an Increasingly Widespread Pathogen

“…In Brazil, where Japanese plum is widespread, the adoption of resistant or tolerant plants appears to be able to reduce the economic impact of PLS and restore the plum production sector. Breeding programs started in the 1990s, crossing cultivars from Florida (United States) and the delta of the Parana River (Argentina) with susceptible local cultivars (Dalbó et al, 2010(Dalbó et al, , 2016(Dalbó et al, , 2018. Unfortunately, initial tolerant cultivars, such as "Carazinho, " "Sanguinea, " "Chatard, " and "Piamontesa, " had a very low-quality production (Dalbó et al, 2016).…”

SCS 438 Zafira - a new plum cultivar resistant to leaf scald (Xylella fastidiosa)

“…Although some cultivars have been reported as resistant, they usually produce low-quality fruits. In addition, the inheritance of resistance is polygenic and predominantly recessive (Dalbó et al 2010).…”