Slow Development Restores the Fertility of Photoperiod-Sensitive Male-Sterile Plant Lines.

Photoperiod- and thermosensitive genic male sterility (P/TGMS) lines are widely used in crop breeding. The fertility conversion of Arabidopsis (Arabidopsis thaliana) TGMS lines including cals5-2, which is defective in callose wall formation, relies on slow development under low temperatures. In this study, we discovered that cals5-2 also exhibits PGMS. Fertility of cals5-2 was restored when pollen development was slowed under short-day photoperiods or low light intensity, suggesting that slow development restores the fertility of cals5-2 under these conditions. We found that several other TGMS lines with defects in pollen wall formation also exhibited PGMS characteristics. This similarity indicates that slow development is a general mechanism of PGMS fertility restoration. Notably, slow development also underlies the fertility recovery of TGMS lines. Further analysis revealed the pollen wall features during the formation of functional pollens of these P/TGMS lines under permissive conditions. We conclude that slow development is a general mechanism for fertility restoration of P/TGMS lines and allows these plants to take different strategies to overcome pollen formation defects.

Combination of direct-ELISA and PCR for the rapid detection and identification of Salmonella spp / 中华预防医学杂志

<p><b>OBJECTIVE</b>To develop a protocol for the rapid detection of Salmonellae.</p><p><b>METHODS</b>A mono-antibody-based direct-ELISA and PCR methods for the detection of Salmonella were developed previously. This study assessed the accuracy of both direct-ELISA and PCR methods for the rapid detection of Salmonella and set up a new detection protocol.</p><p><b>RESULTS</b>The sensitivity of the PCR method was higher than that of direct-ELISA method. In the 2002 spring physical examination for employees, 1 546 human fecal samples were examined by the combination of direct-ELISA and PCR method. Compared with the results of national standard method, the sensitivity and specificity of direct ELISA was 100% and 97.14%, respectively, while those of PCR method reached both 100%. It also indicated that combination use of two methods could give positive report within 40 hrs, and also achieve high sensitivity and specificity.</p><p><b>CONCLUSIONS</b>Based on the results obtained, a protocol for the rapid detection of Salmonella was developed. The first step is to us direct-ELISA method to screen the large number of samples, and then use PCR method to validate the ELISA positive samples, and the final step is, if needed, is to use the national standard method to determine the serotypes of Salmonellae.</p>