Screening And Identification Of Alien Chromosome Lines In Common Wheat Of Chinese Spring Background

Wheat related species contain abundant fine genes,such as Thinopyrum bessarabicum(L?ve JJ or E~bE~b)and Thinopyrum elongatum(Host A.L?ve,EE or E~eE~e),which are resistant to many kinds of wheat diseases,salt tolerance,drought tolerance and so on.It is an important gene bank in wheat genetic improvement.In this study,the combination of in situ hybridization and molecular marker techniques in combination with agronomic traits in the field of 14 wheat-Th.bessarabicum progenies and 16 wheat-Th.elongatum progenies introduced from the CIMMYT and Wheat Resource Center of Kansas State University were identified in order to clarify their genetic composition and make further use of them.The development of excellent genetic resources with stable heredity and excellent traits laid a solid material and theoretical foundation.The main results are as follows:(1)the main agronomic characters in the field showed that the plant height of wheat-Th.bessarabicum progeny lines varied greatly in terms of plant height,which was significantly different from that in China Spring,especially L20160437-1and L20160458 with5J chromosome.The plant height of wheat-Th.elongatum progeny lines was basically the same,and there was no significant difference with the Chinese Spring.The spike length of L20160455-2 and L20160456 was much longer than that of Chinese Spring,but the average number of spikelet was not significantly different,which indicated that the increase of spike length was due to the increase of internode length of spikelet.Under the condition of no obvious difference in mean spikelet number,the average grain number per spike of most materials was significantly higher than that of Chinese Spring,which indicated that the seed setting rate of the above-mentioned materials was higher than that of Chinese Spring.At the same time,special materials were identified,At the same time,special materials were identified,such as L20160436,the color of the grain was blue,which was confirmed by post-identification to add a pair of 4J chromosomes.The 1000-grain weight of L20160947changed significantly relative to the Chinese spring,with an increase of 57.02%,reaching a very significant level.(2)The results of field freeze resistance identification showed that the freeze resistance of China Spring was poor,the leaves were almost dry,and the freezing damage was more serious.The frost resistance survey of 30 materials showed that there were five materials such as L20160438,the degree of dryness of the leaves was between 1/4 and 1/2,which was classified as level 2 freeze damage.nine materials such as L20160437-1 belonged to level 3freeze damage.The freeze resistance of the above materials is significantly improved compared with the Chinese Spring.(3)Under the salt concentration of 2%(350 nmol/mL),thirty samples were tested for salt tolerance during bud stage.Select thirteen materials with salt tolerance better than Chinese spring and salt tolerance grade of 1-2 and further screen at 2.2%salt concentration to obtain 5 high salt tolerances such as L20160455,L20160455-2,L20160456,L20160458-2,L20160941 which were higher in salt tolerance than Chinese spring,involving 1J,3J,5J and3E exogenous chromosomes,lay the foundation for the use of genes related to salt tolerance on alien chromosomes in wheat improvement.(4)Using GISH and FISH techniques,fourteen wheat-Th.bessarabicum progeny germplasm lines and sixteen wheat-Th.elongatum progeny germplasm lines were identified.The results showed that the presence of alien chromosomes was detected in 7 materials such as L20160436.And the number of chromosomes is 2n=44,thereby confirming that the above seven materials are alien addition lines;the presence of alien chromosomes is detected in five materials such as L20160455-2,and the number of chromosomes is 2n=42,thereby confirming the above Five materials are alien substitution lines.In order to determine the homologous group assignment of the alien chromosome,the above 12 materials were identified by molecular marker technique.The results showed that seven disomic addition lines were L20160436 added a pair of 4J,L20160437-1 added a pair of 5J,L20160456 Add a pair of 3J,L20160458 plus a pair of 5J,L20160460-1 add a pair of 6J,L20161461 add a pair of 6E,L20161462 add a pair of 7E.5 disomic substitution lines L20160455-2 is 1J/1B disomic substitution lines,L20160940 is the 4E/4D disomic substitution lines,L20160942 is the 4E/4D disomic substitution lines,L20161457 is the 1E/1D disomic substitution lines,and L20161459 is the 3E/3B disomic substitution lines.