Transcriptome Comparison Reveals Evolutionary Correlation Between Poa Annua and Its Two Diploid Parents, P. Supina and P. Infirma.

Mysterious evolutionary origin, extreme intra-species variability, ubiquitous geological distribution, and extensive environmental adaptability, all of these have made Poa annua one of the most interesting research materials in weed science.  In 1937, John Nannfeldt first raised the idea that P. annua is an allotetraploid hybrid of two diploids, P. infirma and P. supina. This theory was later confirmed by Tomas Tutin, who crossed P. annua with P. infirma and P. supina, and found that meiosis in the pollen mother cells of these triploid hybrids showed in each case, seven bivalents and seven univalents. New evidence from phylogenetic studies confirmed this theory and suggested P. infirma as the female parent. Here, RNA from P. annua, P. infirma and P. supina was sequenced with illumina Hiseq2000. The transcriptomes of the three species were assembled via multiple de novo assemblers. The transcriptome comparison showed strong evidence of evolutionary correlation between P. annua and its two putative parents. Evidence from chloroplast gene comparison also confirmed the theory that P. infirma served as the female parent for P. annua.