in the susceptibility of these dedicated pollenizers to fusarium wilt, caused by the soilborne fungus FON, in commercial fields. Pollenizers susceptible to fusarium wilt appear to produce fewer staminate flowers making them less effective as
Chris Gunter and Daniel S. Egel
Ainhoa Martínez-Medina, Antonio Roldán and Jose A. Pascual
–vermiculite formulation based on T. harzianum (CECT 20714) and the use of this agent as a nonformulated conidia suspension (direct inoculation) were both tested for their potential use as inocula for controlling fusarium wilt and promoting melon plant growth under in
Benjamín Moreno, Cristián Jacob, Marlene Rosales, Christian Krarup and Samuel Contreras
or as a saprophyte in vegetal residues ( Louws et al., 2010 ). Chemical control of fusarium wilt is limited by the number of chemicals available and their effectiveness ( Martyn, 2012 ), and increasing concern about agriculture sustainability
Xianzhi Zhou, Yufen Wu, Sheng Chen, Yang Chen, Weiguang Zhang, Xintao Sun and Yijie Zhao
Oriental melon ( Cucumis melo var. makuwa Makino) is an important germplasm resource of melon in China and is cultivated in Fuzhou (Fujian Province, China) for its delicious sweetness, high nutrient quality, and flavor. Fusarium wilt of Oriental
James D. McCreight, Michael E. Matheron, Barry R. Tickes and Belinda Platts
Three races of Fusarium oxysporum f.sp. lactucae, cause of fusarium wilt of lettuce, are known in Japan, where the pathogen was first observed in 1955. Fusarium wilt first affected commercial U.S. lettuce production in 1990 in Huron, Calif., but did not become a serious problem in the U.S. until 2001 when it reappeared in Huron and appeared in the Yuma, Arizona lettuce production area. Reactions of three fusarium wilt differentials (`Patriot', susceptible to races 1, 2 and 3; `Costa Rica No. 4', resistant to race 1, and susceptible to races 2 and 3; and `Banchu Red Fire', susceptible to races 1 and 3, and resistant to race 2) in a naturally-infected commercial field test and artificially-inoculated greenhouse tests, indicated presence of race 1 in the Yuma lettuce production area. Reactions of these differentials to an isolate from Huron confirmed the presence of race 1 in that area. Consistent with previous results from the U.S. and Japan, `Salinas' and `Salinas 88' were resistant to the Yuma and Huron isolates of race 1, whereas `Vanguard' was highly susceptible. Limited F1 and F2 data indicate that resistance to race 1 in `Costa Rica No. 4' and `Salinas' is recessive. `Calmar' is the likely source of resistance in `Salinas' and `Salinas 88'.
Ju Ding, Kai Shi, Yan-Hong Zhou and Jing-Quan Yu
Cucumber ( Cucumis sativus L.) is one of the major greenhouse vegetables in the world and is very vulnerable to fusarium wilt caused by Fusarium oxysporum (FO) ( Ahn et al., 1997 ; Ye et al., 2004 ). Fusarium pathogen infects the roots and
Samuel F. Hutton, John W. Scott and Gary E. Vallad
. Fusarium wilt, caused by the soilborne fungus Fusarium oxysporum f. sp. lycopersici , has been a major disease of tomato in Florida and in other warm production regions worldwide. The fungus colonizes the vascular tissue of plants after infecting the
Melissa T. McClendon, Debra A. Inglis, Kevin E. McPhee and Clarice J. Coyne
Dry pea (Pisum sativum L.) production in many areas of the world may be severely diminished by soil inhabiting pathogens such as Fusarium oxysporum f. sp. pisi race 1, the causal organism of fusarium wilt race 1. Our objective was to identify closely linked marker(s) to the fusarium wilt race 1 resistance gene (Fw) that could be used for marker assisted selection in applied pea breeding programs. Eighty recombinant inbred lines (RILs) from the cross of Green Arrow (resistant) and PI 179449 (susceptible) were developed through single-seed descent, and screened for disease reaction in race 1 infested field soil and the greenhouse using single-isolate inoculum. The RILs segregated 38 resistant and 42 susceptible fitting the expected 1:1 segregation ratio for a single dominant gene (χ2 = 0.200). Bulk segregant analysis (BSA) was used to screen 64 amplified fragment length polymorphism (AFLP) primer pairs and previously mapped random amplified polymorphic DNA (RAPD) primers to identify candidate markers. Eight AFLP primer pairs and 15 RAPD primers were used to screen the RIL mapping population and generate a linkage map. One AFLP marker, ACG:CAT_222, was within 1.4 cM of the Fw gene. Two other markers, AFLP marker ACC:CTG_159 at 2.6 cM linked to the susceptible allele, and RAPD marker Y15_1050 at 4.6 cM linked to the resistant allele, were also identified. The probability of correctly identifying resistant lines to fusarium wilt race 1, with DNA marker ACG:CAT_222, is 96% percent. These markers will be useful for marker assisted breeding in applied pea breeding programs.
Pamela D. Adams, Nancy Kokalis-Burelle and William H. Basinger
Plantpro 45, an iodine-based compound, was evaluated as a seed treatment for management of fusarium wilt caused by Fusarium oxysporum f.sp. basilici on basil (Ocimum basilicum) in greenhouse assays and for effects on growth of the pathogen in vitro. Plantpro 45 at a concentration of 300 mg·L-1 (ppm) prevented fusarium hyphal growth in vitro. Seed treatments of 800 to 1000 mg·L-1 eliminated fungal contamination of seed and increased germination by 27% compared to the nontreated control. Basil transplants grown from seed treated with 400, 800, and 1000 mg·L-1 were significantly taller, weighed more, exhibited larger leaf area, and had reduced wilt severity in the greenhouse compared to the nontreated control. Transplants grown in soil treated with increasing concentrations of Plantro 45 had correspondingly decreased wilt severity, regardless of whether or not the seeds had been previously treated with Plantpro 45. Further research and optimization of soil and foliar applications in combination with seed treatments are needed to provide a complete program for management of fusarium wilt of basil.
Leigh K. Hawkins, Fenny Dane, Thomas L. Kubisiak and Billy Rhodes
Fusarium wilt, caused by the soilborne fungus Fusarium oxysporum f.sp. niveum (FON), is a serious disease of the watermelon (Citrullus lanatus). Three races of this pathogen (races 0, 1, and 2) have been identified based on differential pathogenicity assays. Most commercially available cultivars are resistant to races 0 and 1. Inheritance for resistance to these races is thought to be controlled by a single dominant gene. No cultivars are resistant to race 2 and resistance is thought to be a quantitative trait. F2 lines derived from a cross between the Fusarium-resistant Citrullus lanatus PI296341, and the Fusarium-susceptible watermelon cultivar `New Hampshire Midget' were used to generate a RAPD-based map of the Citrullus genome. F2:3 families were assayed in the greenhouse for resistance to races 1 and 2. Those families that were either highly resistant or highly susceptible were used in identifying markers linked to Fusarium wilt resistance. A preliminary map of the Citrullus genome based on random amplified polymorphic DNA (RAPD) markers has been expanded with the inclusion of simple sequence repeats (SSRs), amplified fragment length polymorphisms (AFLPs), and isozymes.