Several estimators have been developed for assessing the number of sterility factors in a chromosome based on the sizes of fertile and sterile introgressed fragments. Assuming that two factors are required for producing sterility, simulations show that one of these, twice the inverse of the relative size of the largest fertile fragment, provides good average approximations when as few as five f...

Male sterility is defined as the deviant condition in normally bisexual plants when no viable pollen is formed (Frankel and Galun, 1977). Male sterility has been exploited as an effective tool to aid hybrid seed production in many crops. Using this trait, seed producers can transform one inbred from a planned hybridization into a “female” line, thereby ensuring seed of hybrid origin on the male...

Objective: To examine the qualitative and quantitative characteristics of frozen-thawed spermatozoa recovered through the SpermPrep (ZBL, Inc., Lexington, KY) filtration method or the swim-up technique for the purpclse of intrauterine insemination (IUI) or other techniques for assisted reproduction. Design, Setting, Patients: Thirty pairs of frozen specimens purchased from three commercial seme...

Received June 5, 2001; revised and accepted October 16, 2001. Reprint requests: Wolfgang E. Paulus, M.D., Christian-Lauritzen-Institut, Frauenstr. 51, D-89073, Ulm, Germany (FAX: ++49-731-9665130; E-mail: [email protected]). [a] Department of Reproductive Medicine, Christian-Lauritzen-Institut. [b] Department of Traditional Chinese Medicine, Tongji Hospital, Tongji Medical University, Wuhan, P...

S tcrility of a drug product, in the strictest sense, is defined as "complete absence of microorganisms in the product." However, the test for sterility as described in the Pharmacopoeias [I], is not a test on which any strong reliance can be based tor sterility assurance of the product. Due to limitations in testing [2]. the test for sterility is not a suitable release test to verify that a pr...

The experiment was conducted to investigate potential causes of grain sterility in widely cultivated rice variety in Malaysia, MR219 and its two mutant lines (RM311 and RM109) by examining the source-sink relations. RM311 produced increased dry matter yield both at heading and maturity and also showed higher grain yield with greater proportion of grain sterility than the other two genotypes (RM...

The development of strategies to improve crop plants by the production of hybrid varieties is a major goal in plant breeding. Hybrid progeny often have a higher yield, increased resistance to disease, and an enhanced performance in different environment compared with the parental lines. Availability of cost effective mechanism/ method to produce large scale hybrid seed utilizing selected parent...

Haldane's rule (i.e., the preferential hybrid sterility and inviability of heterogametic sex) has been known for 70 years, but its genetic basis, which is crucial to the understanding of the process of species formation, remains unclear. In the present study, we have investigated the genetic basis of hybrid male sterility using Drosophila simulans, Drosophila mauritiana and Drosophila sechellia...

F1 hybrid females between the sibling species Drosophila simulans, Drosophila mauritiana and Drosophila sechellia are completely fertile. However, we have found that female sterility can be observed in F2 backcross females who are homozygous for D. simulans X chromosomes and homozygous for autosomal regions from either D. mauritiana or D. sechellia. Our results indicate that neither D. mauritia...