Genetic Analysis of Main Physiological and Morphological Traits

Abstract

Wheat physiological and morphological traits are the most important traits for wheat (Triticum aestivum L.) yield. In this chapter, quantitative trait loci (QTL) mapping for physiological traits including photosynthetic Characters, microdissection characteristics of Stem, heading date and cell membrane permeability of leaf, and for morphological traits of containing root-related traits and leaf-related traits were analyzed in different environments using the DH population, RIL population or natural population. Photosynthesis related traits of wheat were mapped under field and phytotron environments, respectively. Eight additive QTLs and three pairs of epistatic QTLs for chlorophyll were detected in field environments and 17 additive QTLs for conferring photosynthesis and its related traits were identified in phytotron environments. Furthermore, 18 additive loci for dry matter production (DMA) and Fv/Fm were detected. For microdissection characteristics of wheat stem, a total of 12 QTLs controlling anatomical traits of second basal internode on chromosomes 1B, 4D, 5B, 5D, 6A and 7D, and 20 additive QTLs for anatomical traits of the uppermost internode on chromosomes 1A, 1B, 2A, 2D, 3D, 4D, 5D, 6A, 6D and 7D were detected based on DH population. Two additive QTLs on chromosomes 1B and 5D in DH population, five additive QTLs on chromosomes 3B, 5B, 6A, 6B and 7D in RIL population derived from the cross of Nuomai 1 × Gaocheng 8901 and 12 additive QTLs on chromosomes 1A, 1B, 4B, 6A and 6B based on a RIL population derived from the cross of Shannong 01-35 × Gaocheng 9411 were identified for heading date. For cell membrane permeability of leaf, a total of 21 additive QTLs were detected on chromosomes 1B, 2A, 3A, 3B, 5B, 6A, 6B, 6D, 7B and 7D, respectively in three different environments based on a DH population. Seven additive QTLs and 12 pairs of epistatic QTLs for root-related traits were mapped on chromosomes 1A, 1D, 2A, 2B, 2D, 3A, 3B, 5D, 6D and 7D using IF2 population derived from Huapei 3 × Yumai 57.31 additive QTLs and 22 pairs of epistatic QTLs conferring leaf morphology were detected based on a DH population. Finally, by genome-wide association analysis with a natural population derived from the founder parent Aimengniu and its progenies, 61 marker-trait associations (MTAs) involving 46 DArT markers distributed on 14 chromosomes (1B, 1D, 2A, 2B, 2D, 3A, 3B, 4A, 5B, 6A, 6B, 6D, 7A and 7B) for leaf-related traits were identified and the R2 ranges from 0.1 to 16.4 %. These results provide a better understanding of the genetic factors for wheat physiological and morphological traits and facilitate marker-assisted selection strategy in wheat breeding.