Phenotypic Characterization And Gene Preliminarily Mapping Of Rolled Leaf Mutant Swl4 In Maize

Leaf curl is one of the important agronomic traits of plants.Moderate curling leaves helps to improve the photosynthetic efficiency and thus increase crop yield.The leaf curl can be divided into two different types,i.e.physiological leaf curl and genetic leaf crul.The former type is mainly induced by the external environment,such as drought,high temperature,disease,etc.It is a self-defense of the plant.When the external stress disappears,the curled leaf will be return to the natural state.However,the latter type is mainly caused by genetic factors,and the phenotype is usually irreversible.At present,the genetic mechanism of curled leaf has been studieda lot,and some rollled leaf mutants have been isolated using model plants.However,rolled leaf in maize are seldom reported.Here a curl leaf mutant swl4(sensitive to water loss)was identified.Compared to WT,the mutant showed curl,whiter and softer leaves in the field,The F2 population of swl4 and WT show 3:1 seperating ratio,indicating that swl4 is a single recessive gene mutant.By measuring the stomatal opening and closing state,stomatal density and relative water content of the swl4 mutant,it was found that SWL4 may affect the photosynthesis and transpiration efficiency.Using the swl4 mutant and the conventional inbred lines Zheng58,Chang7-2,and Zong31 to construct F2 population,SWL4 were mapped within the interval 158 Mb of 165 Mb on chromosome 7.Subsequently,the marker was developed in the interval of 158-165 Mb,and the target region was narrowed down between the two In Del markers of Ind61 and Ind63,The physical distance of the two In Del markers on the maize B73 reference genome(V3 version)was 7 Mb.This study provides a basis for the follow-up cloning of SWL4 gene.