Genetic diversity and relatedness of mango cultivars assessed by SSR markers.

Assessment of genetic diversity and relatedness is an essential component of germplasm characterization and use. We analyzed 120 mango (Mangifera indica L.) genetic resources in Japan for their parentage, cultivar identification, genetic relatedness, and genetic diversity, using 46 polymorphic simple sequence repeat (SSR) markers. Ten sets of three SSR markers could successfully distinguish 83 genotypes with the exception of synonymous and identical accessions. We successfully assessed parentage, newly identifying or reconfirming both parents of 11 accessions, and revealing over 30 cultivars as offspring of 'Haden'. Genetic relatedness and diversity analyses revealed three distinct clusters. Two clusters correspond to the groups of USA and India, which are closely related. The other includes accessions from Southeast and East Asia. The results agree with the previous identification of genetically distinct Indian and Southeast Asian types, and suggest that the Florida accessions, which originated from hybrids between those two types, are more closely related to the Indian type.

Efficacy of long-term 4.0 g/day mesalazine (Pentasa) for maintenance therapy in ulcerative colitis.

BACKGROUND: High-dose (4.0 g/day) mesalazine is typically used for induction therapy, but its efficacy as maintenance therapy remains to be determined. We conducted a multicenter retrospective study to investigate the efficacy of continuous treatment with 4.0 g/day of mesalazine. MATERIAL/METHODS: Japanese ulcerative colitis (UC) patients receiving acute induction therapy with 4.0 g/day mesalazine were enrolled and followed. Those who clinically improved or who achieved clinical remission were categorized into 2 sub-groups according to the median duration of treatment with 4.0 g/day of mesalazine. The clinical relapse frequency and the time to relapse were analyzed. RESULTS: We enrolled 180 patients with active UC, and then 115 patients who clinically improved or who achieved clinical remission after treatment with 4.0 g/day mesalazine were categorized into 2 sub-groups according to the median of treatment duration: a short-term treatment group (≤105 days, n=58) and a long-term treatment group (>105 days, n=57). Overall, 45 (39.1%) patients relapsed: 28 (48.3%) in the short-term treatment group and 17 (29.8%) in the long-term treatment group. This difference was statistically significant (p<0.05). The relapse-free rate in the long-term treatment group was significantly higher than that in the short-term treatment group (p<0.05). The mean time to relapse in the long-term treatment group was significantly longer than that in the short-term treatment group (425.6±243.8 days vs. 277.4±224.5 days; p<0.05). CONCLUSIONS: Long-term continuous treatment with high-dose mesalazine (4.0 g/day) may be more effective than short-term treatment for maintenance of remission in UC patients.