Evaluation of genetic variability for sclerotinia sclerotiorum (Lib) de Bary resistance in sunflower and utilization of associated molecular markers

Abstract

In the framework of a bilateral project Italy -Romania (University of Udine and IC), an experiment was established at the University of Udine Experiment Station in order to: i) evaluate the genetic variability of the tested genotypes for Sclerotinia basal stem and head infection; ii) to test two new alternative screening methods against white head rot; iii) to investigate possible relationships among the different tests; iiii) to find resistance-associated fragments by AFLP analysis.The following tests were used: 1) basal stem infection, 2) ascospore head infection, 3) mycelium culture filtrate injection and 4) oxalic acid injection into the back face of the head.The segregation of responses between resistant and susceptible controls displayed the suitability of mycelium and ascospore tests adopted and the independence of the two tolerance mechanisms.Conversely, tests 3 and 4 showed a poor discrimination of the controls and a complete lack of relationships with mycelium and ascospore infections. Sunflower reaction against S. sclerotiorum may not be restricted to resistance to oxalic acid, but may involve other physiological mechanisms.The inbred line 28R (coming from H. argophyllus wild species) was not only most tolerant against both, basal stem and white head rot infections, but also it gave the best performance in oxalate and culture filtrate tests highlighting a specific resistance to oxalate.

Reaction of brazilian cotton genotypes to white mold depends on pathogen aggressiveness and incubation conditions

“…Possibly, solutions that are more concentrated would be required, in contrast to what was recommended for common beans and soybeans (KOLKMAN;KELLY, 2000;ANTÔNIO et al, 2008;HÜLLER et al, 2016;SOUZA et al, 2016). The inconsistency of the oxalic acid method discourages the indirect evaluation of cotton resistance to white mold, be it by need to optimize the technique or by the combination with other physiological mechanisms of resistance in cotton, such as biosynthesis of phytoalexins, shikimic acid, phenolic compounds or oxalate detoxification (BALDINI et al, 2002;CUNHA et al, 2010;DAVIDSON et al, 2016).…”

“…There are proteomics, metabolomics and transcriptomics reports of the interactions Sclerotinia-Glycine max (L.) Merrill, Sclerotinia-Phaseolus vulgaris L., Sclerotinia-Helianthus annuus L. and Sclerotinia-Brassica napus L. (PELUFFO et al, 2010;GARG et al, 2013;OLIVEIRA et al, 2015;CAO;XU;CAI, 2016;JOSHI et al, 2016a;WU et al, 2016). Even the selection of genes and genotypes resistant to the fungus overlook cotton while including alfalfa (PRATT; ROWE, 1991), peanut (AKEM; MELOUK; SMITH, 1992), sunflower (ACHBANI;DE LABROUHE;VEAR, 1994;BALDINI et al, 2002;DAVAR et al, 2011), lentil (AKEM; BELLAR; BAYAA, 2006), peas (PORTER; HOHEISEL; COFFMAN, 2009), okra (FISCHER et al, 2014), canola (AHMADIFAR;DALIL, 2013;WU et al, 2013;JOSHI et al, 2016b), common beans (LEITE, 2014;ABREU, 2016) and soybeans (GARCIA;JULIATTI, 2012;BASTIEN;SONAH;BELZILE, 2014;JULIATTI et al, 2014;IQUIRA;HUMIRA;FRANÇOIS, 2015;CASTRO et al, 2016;WEI et al, 2017).…”

Sunflower Breeding for Resistance to Abiotic and Biotic Stresses

“…Using four different tests for the evaluation of Sclerotinia resistance (basal stem infection, ascospore, and oxalic acid injection into the back face of the head), Baldini et al [72] found that the inbred line 28R was most tolerant to the basal stem and white head rot infections and it also showed the best performance in oxalate and culture filtrate tests, which indicated the presence of a specific resistance to oxalate.…”

Transgenic Sunflower

“…Research involving the heads of infected plants has shown that tolerance to white rot is related to the accumulation of phenolic (Prats et al 2003) and coumarin compounds (Prats et al 2006) and to the absence of the phytotoxic effect of oxalic acid (Baldini et al 2002). Oxalic acid concentration increases when tissues are damaged and this can be used as an indirect method for selecting on the basis of tolerance to disease (Vasic et al 2002).…”