Characterization of salt tolerance and Fusarium wilt resistance of a sweetpotato mutant

The variant LM1 was previously obtained using embryogenic cell suspension cultures of sweetpotato variety Lizixiang by gamma-ray induced mutation, and then its characteristics were stably inherited through six clonal generations, thus this mutant was named LM1. In this study, systematic characterization of salt tolerance and Fusarium wilt resistance were performed between Lizixiang and mutant LM1. LM1 exhibited significantly higher salt tolerance compared to Lizixiang. The content of proline and activities of superoxide dismutase（SOD） and photosynthesis were significantly increased, while malonaldehyde（MDA） and H_2O_2 contents were significantly decreased compared to that of Lizixiang under salt stress. The inoculation test with Fusarium wilt showed that its Fusarium wilt resistance was also improved. The lignin, total phenolic, jasmonic acid（JA） contents and SOD activity were significantly higher, while H_2O_2 content was significantly lower in LM1 than that in Lizixiang. The expression level of salt stress-responsive and disease resistance-related genes was significantly higher in LM1 than that in Lizixiang under salt and Fusarium wilt stresses, respectively. This result provides a novel and valuable material for improving the salt tolerance and Fusarium wilt resistance of sweetpotato.

Identification of Molecular Markers Linked to the Wilt Resistance Gene FuJ7(t) in Flax

A cross between wilt resistant flax variety Jinya7 and susceptible variety Jinya1 wasmade for mapping wilt resistance gene(s). The inoculation test of F1 and F2 progeny provedthat the resistance of Jinya7 to wilt is controlled by two dominant genes. With 48 EcoRⅠ/MseⅠ primer combinations, amplified fragment length polymorphisms (AFLP) analysis wasperformed on two parents and their F2 resistance and susceptibility bulks. A total ofabout 3300 distinguishable bands were amplified, of which three bands had stabledifferences. The genetic linkage analysis of the three polymorphic DNA fragments withthe resistance gene(s) was made in the F2 segregating population derived from the crossbetween Jinya7 and Jinya1. The DNA fragment AG/CAG was found closely linked to one of thewilt-resistant genes, which with a genetic distance of 5.2cm, was tentatively named FuJ7(t).The cloned fragment AG/CAG was sequenced and then converted successfully to a sequencecharacterized amplified region (SCAR) marker, which can be used more conveniently in theidentification and marker-assisted selection for the wilt resistance gene FuJ7(t) toflax wilt.

QTL Analysis of Fiber Yield and Quality and Resistance to Verticillium Wilt Using Gossypium hirsutum and G.barbadense Advanced Backcross Populations

To introgress elite QTL alleles of Gossypium barbadense L.for fiber yield and quality and resistance to Verticillium wilt into G.hirsutum L.,enlarge the genetic base of G.hirsutum,and

Test on Wilt-Resistance of Simple Hybrides F7 and Beckross Hybrid Lines F6 B1 of <i>G. hirsutum</i>L. of Cotton to New Virulent Isolates of Fungus <i>Fusarium verticillioides</i>and <i>Verticillium dahliae</i>

The article presents the results of studies on the resistance of hybrid cotton lines to a new virulent isolate (strain) of the fungus Fusarium verticillioides upon inoculation of the host plant. Based on the studies, it was found that the complex genotypic resistance of the studied lines, when the host plants are inoculated with isolates of -100 V. dahliae Kleb fungus and 103 Fusarium verticillioides fungi, depends on the degree of resistance of the parental forms and their combination ability.

Studies on Cotton Breeding Resistant to Fusarium and Verticillium wilt Diseases

Both Fusarium and Verticillium wilts are important soil-borne diseases,which can not be effectively controlled by chemical fungicides.The two diseases,especially Verticillium wilt,have