Effect of sex,temperature,time and flock size on the diving behavior of the wintering Scaly-sided Merganser(Mergus squamatus)

Background: The foraging and diving behavior of waterfowl are affected by a number of important factors. Hence, learning more about these major factors is of great concern in order to protect endangered species. In this study, we verified the effect of sex, temperature, time and flock size on the diving behavior of the Scaly-sided Merganser(Mergus squamatus).Methods: The study was conducted by means of focal animal sampling in the Wuyuan section of the Poyang Lake watershed in Jiangxi Province, China from December 2015 to March 2016. We used one-way ANOVA and LSD tests to investigate the differences among these factors. Pearson correlations were used to test the relation between pause duration and the previous or subsequent dive duration. The relations between these factors and dive/pause duration are illustrated using Spearman correlations.Results: Mean dive duration and mean time on the pause of males were significantly higher than those of females. With an increase in temperature, dive duration significantly increased. Along with the passage of time of year and daytime, dive duration significantly increased, while dive duration decreased significantly with the increase in flock size.Conclusions: Sex, temperature, time and flock size have an effect on the diving behavior of the wintering Scalysided Merganser. The difference of diving behavior between males and females is related to differences in body mass. The difference of diving behavior among various temperatures and time periods may be related to a low minimum rate of oxygen consumption, while the difference among various flock sizes may be caused by rising intraspecific competition.

Development of diagnostic markers for a wheat leaf rust resistance gene Lr42 using RNA-sequencing

Wheat leaf rust is a prevalent foliar disease in wheat worldwide. Growing resistant cultivars is an effective strategy to minimize the impact of leaf rust on yield and grain quality. Lr42 is a leaf rust resistance gene identified from Aegilops tauschii and is still effective against current predominant leaf rust races in the United States and many other countries. In this study, we developed diagnostic DNA markers for Lr42 using the sequence polymorphisms of a differentially expressed gene(TaRPM1) encoding a putative NBARC protein in the Lr42 candidate region identified by RNA-sequencing of two near-isogenic lines contrasting in Lr42 alleles. Markers were designed based on a deletion mutation and a single nucleotide polymorphism(SNP) in the gene. Haplotype analyses of the newly developed markers in the three diversity panels demonstrated that they are diagnostic for Lr42, and superior to previously used markers in selection accuracy. These markers have the advantages of low cost and easy assay, and they are suitable for marker-assisted selection in breeding programs with either high-or low-throughput marker screening facilities.