[Stable expression of QTL for grain shape of milled rice (Oryza sativa L. ) using a CSSLs population].

A set of chromosome segment substitution lines (CSSLs), derived from Asominori/IR24 with Asominori as the recurrent parent,was planted and phenotyped for grain length (GL), grain width (GW) and length-width ratio (LWR) of milled rice in two successive years and four sites. QTL for GL,GW and LWR were characterized and stability of their expression was investigated. The phenotypic values for each trait showed a continuous distribution and some transgressive lines were also observed in the CSSLs population. Additionally, a total of 13 QTL for GL, GW and LWR were identified,and six of them were consistently detected in the eight different environments. Phenotypic values were different significantly (P < 0. 001) between the CSSLs harboring any of the six QTL alleles and the genetic background parent, Asominori. Significant phenotypic correlations (r > or = 0.75, r0.05 = 0.67) were detected among different environments for these CSSLs carrying the same target QTL. Also, the results indicated that the six QTL, namely, qGL-3 for GL, qGW-5a and qGW-5b for GW, qLWR-3, qLWR-5a and qLWR-5b for LWR, were stably expressed in different environments. Since QTL qGL-3 and qLWR-3 were mapped in the R19-C1677 interval, qGW-5a and qLWR-5a in the vicinity of RFLP marker C263, qGW-5b and qLWR-5b near R569,the four RFLP markers, R19, C1677, C263 and R569,would be useful for further marker-assisted selection (MAS) in rice quality improvement.

ASTHMATIC CHILDREN AND SWIMMING / 体力科学

In 31 asthmatic children, we investigated the change of the structure on the time of living, an amount of exercise by pedmeter and measured pulmonary ventilatory function during 28 weeks swimming training.<BR>The result showed 58.07% of contribution factor to the structure on the time of living on children with asthma and dynamic play time after school were significantly shorter in asthmatic than non-asthmatic children (p<0.05) . After 28 weeks, we could not find any significantly differences of dynamic play time between asthmatic and nonasthmatic children.<BR>An amount of exercise in daily life from the point of view of walking step number by pedmeter were significantly less in aged 6-9 years boys and girls, and aged 10-12 years boys than non-asthmatic children (respectively, p<0.05, p<0.01) . However, after 28 weeks, we could not find any differences between asthmatic and non-asthmatic children.<BR>Forced vital capacity (FVC) and rate of forced expiratory volume on one second (% FEV<SUB>1.0</SUB>) were increased after 28 weeks than the begining of swimming, and we found the strength of their breathing muscles.<BR>On according to perform the great swimming distances (averages 220m in boys, 325m in girls), all asthmatic children became very lively and actively.