Muhammad Qasim Shahid
South China Agricultural University , China
Title: Molecular and cytological studies on pollen development in autotetraploid rice
Biography
Biography: Muhammad Qasim Shahid
Abstract
Autotetraploid rice has a great genetic potential to increase the rice production, but lower pollen fertility is a major barrier in its utilization. Intersubspecific autotetraploid rice hybrids showed greater genetic variation compared to their diploid counterparts. Here, we observed the pollen development and its relation with seed set in autotetraploid rice. Microgametogenesis in autotetraploid rice was similar to diploid rice, but different kinds of abnormalities, including microspores degeneration, cytoplasm shrinkage and abnormal cell walls, were found in autotetraploid rice. Many different kinds of chromosomal abnormalities were found during various development stages of pollen mother cell meiosis such as chromosome lagging, chromosome straggling, pre-separation of two chromosome set, randomly arranged chromosome on the equator, abnormal spindle, and incomplete/no separation of cytokinesis. We identified meiosis-related or meiosis-stage-specific genes that were down-regulated in polyploid rice. Gene ontology analysis on the targets of up-regulated DEM showed that they were enriched in transport and membrane in pre-meiotic interphase, reproduction in meiosis, and nucleotide binding in single microspore stage. Quantitative RT-PCR was used to validate differentially expressed genes and microRNAs selected from functional categories based on the gene ontology analysis and the results showed that their expression patterns were consistent with the microarray data and high-throughput sequencing, respectively. These findings provide a foundation for understanding the effect of polyploidy on meiosis-related genes and miRNAs expression patterns during pollen development that lead to low pollen fertility in autotetraploid rice.