Abstract
The objective of this work was to determine soybean resistance inheritance to Heterodera glycines Ichinohe (soybean cyst nematode - SCN) races 3 and 9, as well as to evaluate the efficiency of direct and indirect selection in a soybean population of 112 recombinant inbred lines (RIL) derived from the resistant cultivar Hartwig. The experiment was conducted in a completely randomized design, in Londrina, PR, Brazil. The estimated narrow-sense heritabilities for resistance to races 3 and 9 were 80.67 and 77.97%. The genetic correlation coefficient (r g = 0.17; p<0.01) shows that some genetic components of resistance to these two races are inherited together. The greatest genetic gain by indirect selection was obtained to race 9, selecting to race 3 due to simpler inheritance of resistance to race 9 and not because these two races share common resistance genes. The resistance of cultivar Hartwig to races 3 and 9 is determined by 4 and 2 genes, respectively. One of these genes confers resistance to both races, explaining a fraction of the significant genetic correlation found between resistance to these SCN races. The inheritance pattern described indicates that selection for resistance to SCN must be performed for each race individually.
Highlights
Soybean cyst nematode (Heterodera glycines Ichinohe – SCN) is a pathogen that affects soybean production worldwide with losses that reached 9 million tons in 1998 (Wrather et al, 2001)
Differentials and susceptible control were used as monitor the SCN populations and their responses remained consistent while no race shifts occurred
With n - 2 degrees of freedom and a level of significance of 1%, where n is the total number of recombinant inbred lines (RIL)
Summary
Soybean cyst nematode (Heterodera glycines Ichinohe – SCN) is a pathogen that affects soybean production worldwide with losses that reached 9 million tons in 1998 (Wrather et al, 2001). Sources of resistance to SCN were reported first by Ross (Ross & Brim, 1957). Three recessive genes were reported as responsible for resistance to race 1 in cultivar Peking (Caldwell et al, 1960). That confers resistance to race 3 (Rhg4) and 4 (currently race 14) was found by Matson & Williams (1965) and Thomas et al (1975), respectively. Hancock et al (1987) reported one more recessive gene associated with resistance to “race X”. The resistance to race 3 in PI 88788 is conditioned by
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
