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Genetic analysis of heat tolerance will help breeders produce rice (Oryza sativa L.) varietes adapted to future climates. An F6 population of 181 recombinant inbred lines of Bala (tolerant) x Azucena (susceptible) was screened for heat tolerance at anthesis by measuring spikelet fertility at 30°C (control) and 38°C (high temperature) in experiments conducted in the Philippines and the United Kingdom. The parents varied significantly for absolute spikelet fertility under control (79-87%) and at high temperature (2.9-47.1%), and for relative spikelet fertility (high temperature/control) at high temperature (3.7-54.9%). There was no correlation between spikelet fertility in control and high-temperature conditions and no common quantitative trait loci (QTLs) were identified. Two QTLs for spikelet fertility under control conditions were identified on chromosomes 2 and 4. Eight QTLs for spikelet fertility under high-temperature conditions were identified on chromosomes 1, 2, 3, 8, 10, and 11. The most significant heat-responsive QTL, contributed by Bala and explaining up to 18% of the phenotypic variation, was identified on chromosome 1 (38.35 mega base pairs on the rice physical genome map). This QTL was also found to influence plant height, explaining 36.6% of the phenotypic variation. A comparison with other studies of abiotic (drought, cold, salinity) stresses showed QTLs at similar positions on chromosomes 1, 3, 8, and 10, suggesting common underlying stress-responsive regions of the genome. [ABSTRACT FROM AUTHOR]

Every year, thousands of people in great Britain go for the first time to clinics provided by the Family Planning Association in order to get birth control advice. This article assesses the contribution made by clinics to the birth control behavior of the British people. The method adopted was to establish a Working Party to review the aims and objectives, constitution, organization and services of the Association. Information was sought through a series of questionnaires and statistical returns. Data were classified so as to permit their dovetailing with the demographic data about the population as a whole.