Towards producing perennial wheat using wild species for breeding in arid land

摘要

Most cereal crops such as wheat and maize are annual.They grow from seeds,produce seeds for propagation in the next generation,and thus the life cycle is closed.This feature of annual plants necessitates soil tillage for sowing seeds in field,which has economic and environmental costs.If the plants were perennial,these problems could be avoided.Long and dense rhizosphere which is a feature of perennial plants must facilitate improvement of soil cohesion and water holding capacity and nutrient status in arid regions.Leymus mollis(2n=4x=28,NsNsXmXm),a wild species related to wheat,is perennial and distributed in the seaside.This plant has strong and long roots and is tolerant to salinity and heat.It grows vigorously and is propagated by producing robust rhizome.To transfer the useful features of L.mollis into wheat,we produced hybrids(n=5x=35)between L.mollis and wheat cultivar ‘Norin 61’(2n=6x=42,AABBDD).The hybrids have perennial nature.The hybrids were backcrossed with Norin 61 and we obtained only one seed of BC1F1 generation.The BC1F1 plant was fertile,and thus the selfed seeds(BC1F2)could be produced.We found that some of the BC1F2 plants produced new tillers after harvesting seeds like perennial plants.We have been investigating the nature of the plants.