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MicroRNAs (miRNAs) are small non-coding endogenous riboregulators that play significant roles in plant growth, development, metabolism, defense, and stress responses. Upland cotton is best known for its economic value as natural fiber and oil. It is also an important model for genome evolution, polyploidy effects, cell growth, and cell wall biosynthesis. The polyploid species, Gossypium hirsutum L. (2n = 52), evolved from two progenitors (2n = 26), one contributing an ancestral genome similar to A genomes of G. herbaceum and G. arboreum, and the other like the D genome of G. raimondii. There is much to be learned about Gossypium miRNAs and their gene targets, about the effects of polyploidy and their practical ramifications. In this study, small-RNA (sRNA) libraries from four Gossypium species and three tissue libraries (seed, seedling, and leaf) from G. hirsutum were constructed and analyzed using high-throughput sequencing with Illumina/MiSeq then computational prediction by MIREAP. Results showed 245 known miRNAs belonging to 67 miRNA families and 149 novel (non-redundant and redundant) miRNAs derived from 394 genomic loci. This unified study identified 21 and 33 conserved miRNA families across four Gossypium species and three tissue libraries, respectively. Similar to canonical miRNAs, the 5′ of novel miRNAs had the higher preference for U and A residues. In this study, 551 potential target genes were predicted in 45 conserved miRNA families, while 439 targets were associated with 113 novel miRNAs. The majority of the conserved (34%) and novel (22%) miRNA targets identified belonged to cellular processes and signaling. However, the functional diversity of novel miRNA targets is attributed to the tissue and species bias. Most of the identified targets were regulated by mRNA cleavage than by translational repression. These results provide a basis for better understanding regulatory networks in upland cotton (G. hirsutum) and its closest progenitors. Keywords: Cotton, Progenitor, Sequencing, Prediction, MIREAP, sRNA, miRNA, Family, Known, Novel, Gene regulation, Target

Satellite-based precipitation products are expected to offer an alternative to ground-based rainfall estimates in the present and the foreseeable future. In this paper, we evaluate the performance of TRMM 3B42 precipitation products in the Yangtze River basin for the period of 2003~2010. The results are as follows: (1) the performance of RTV7 (V7) products is generally better than that of RTV6 (V6) in the Yangtze River basin, and the percentage of best performance (bias ranging within −10%~10%) for the annual mean precipitation increases from 21.72% (54.79%) to 36.70% (59.85%) as the RTV6 (V6) improved to the RTV7 (V7); (2) the TMPA products have better performance in the wet period than that in the dry period in the Yangtze River basin; (3) the performance of TMPA precipitation has been affected by the elevation and a downward trend can be found with the increasing elevation in the Yangtze River basin. The average CC between the V7 and observed precipitation in July decreases from 0.71 to 0.40 with the elevation of gauge stations increasing from 500 m below to 4000 m above in the Yangtze River basin. More attention should be paid to the influence of complex climate and topography.