A Genetic Linkage Map of BC2 Population Reveals QTL Associated with Plant Architecture Traits in Lagerstroemia

Yang Zhou,Tangren Cheng,Lu Feng,Ye Zhang,Jia Wang,Jieru Liu,Qixiang Zhang,Ming Cai,Qifang Lin,Huitang Pan,Yuanjun Ye

doi:10.3390/f12030322

Abstract

Plant architecture improvement is of great significance in influencing crop yield, harvesting efficiency and ornamental value, by changing the spatial structure of the canopy. However, the mechanism on plant architecture in woody plants is still unclear. In order to study the genetic control of plant architecture traits and promote marker-assisted selection (MAS), a genetic linkage map was constructed, and QTL mapping was performed. In this study, using 188 BC2 progenies as materials, a genetic map of Lagerstroemia was constructed using amplification fragment length polymorphisms (AFLP) and simple sequence repeats (SSR) markers, and the QTLs of four key plant architecture traits (plant height, crown width, primary lateral branch height and internode length) were analyzed. The genetic map contains 22 linkage groups, including 198 AFLP markers and 36 SSR markers. The total length of the genome covered by the map is 1272 cM, and the average distance between markers is 6.8 cM. Three QTLs related to plant height were located in LG1, LG4 and LG17 linkage groups, and the phenotypic variation rates were 32.36, 16.18 and 12.73%, respectively. A QTL related to crown width was located in LG1 linkage group, and the phenotypic variation rate was 18.07%. Two QTLs related to primary lateral branch height were located in the LG1 and LG7 linkage groups, and the phenotypic variation rates were 20.59 and 15.34%, respectively. Two QTLs related to internode length were located in the LG1 and LG20 linkage groups, and the phenotypic variation rates were 14.86 and 9.87%. The results provide a scientific basis for finely mapping genes of plant architecture traits and marker-assisted breeding in Lagerstroemia.

Highlights

Plant architecture refers to the morphological characteristics of various tissues and organs of the above-ground part of the plant and their arrangement, including plant height, crown width, primary lateral branch height, internode length, etc
The wheat green revolution gene rht leads to suppression of wheat cell elongation and shortening of the stems, inducing lodging resistance and increased yield, but it leads to the production of a large number of ineffective tillers and light blocking and competition among the leaves [9]
We evaluated internode length for each individual from three different orientations and selected annual branches

Summary

Introduction

Plant architecture refers to the morphological characteristics of various tissues and organs of the above-ground part of the plant and their arrangement, including plant height, crown width, primary lateral branch height, internode length, etc. Plant architecture is important for improving yield, environmental adaptability, and competitiveness, and for enriching ornamental horticulture [2,3]. Tiller is a unique research trait in rice, and its number and angle affect rice plant architecture. MOC1 is an important gene controlling rice tillers. The wheat green revolution gene rht leads to suppression of wheat cell elongation and shortening of the stems, inducing lodging resistance and increased yield, but it leads to the production of a large number of ineffective tillers and light blocking and competition among the leaves [9]. The TB1 gene in maize has extremely reduced the number of branches, resulting in a species with only one main stem at present, which has become an important cultivated crop for humans [10]. A reasonable plant height and ear height ratio can effectively increase the yield [11]

Methods

Results

Discussion

Conclusion