| assessment of the genetic diversity of xylella fastidiosa isolated from citrus in brazil by pcr-rflp of the 16s rdna and 16s-23s intergenic spacer and rep-pcr fingerprinting. | the genetic diversity among twenty three strains of xylella fastidiosa, isolated from sweet orange citrus, was assessed by rflp analysis of the 16s rdna and 16s-23s intergenic spacer and by rep-pcr fingerprinting together with strains isolated from coffee, grapevine, plum and pear. the pcr products obtained by amplification of the 16s rdna and 16s-23s spacer region were digested with restriction enzymes and a low level of polymorphism was detected. in rep-pcr fingerprinting, a relationship betwe ... | 2001 | 11392484 |
| etiology of three recent diseases of citrus in são paulo state: sudden death, variegated chlorosis and huanglongbing. | the state of são paulo (ssp) is the first sweet orange growing region in the world. yet, the ssp citrus industry has been, and still is, under constant attack from various diseases. in the 1940s, tristeza-quick decline (t-qd) was responsible for the death of 9 million trees in ssp. the causal agent was a new virus, citrus tristeza virus (ctv). the virus was efficiently spread by aphid vectors, and killed most of the trees grafted on sour orange rootstock. control of the disease resided in replac ... | 2007 | 17505974 |
| diversity of endophytic yeasts from sweet orange and their localization by scanning electron microscopy. | endophytes are microorganisms that colonize plant tissues internally without causing harm to the host. despite the increasing number of studies on sweet orange pathogens and endophytes, yeast has not been described as a sweet orange endophyte. in the present study, endophytic yeasts were isolated from sweet orange plants and identified by sequencing of internal transcribed spacer (its) rrna. plants sampled from four different sites in the state of são paulo, brazil exhibited different levels of ... | 2009 | 19798655 |