裂叶地黄四倍体种质创制及与地黄远缘杂交研究OA

Objective:To broaden the genetic basis of Rehmannia glutinosa varieties,the autotetraploid Rehmannia piasezkii was obtained by chromosome doubling,and the tetraploid Rehmannia piasezkii was used for distant hybridization with Rehmannia glutinosa,and excellent germplasm resources were created by continuous backcrossing with Rehmannia glutinosa.Methods:Tetraploid Rehmannia piasezkii was obtained by treating the seeds of Rehmannia piasezkii(2x=28)with colchicine.The hybrids were obtained by distant hy-bridization between tetraploid Rehmannia piasezkii and Rehmannia glutinosa.Excellent lines were screened and backcrossed with Reh-mannia glutinosa for two times to obtain new germplasms exhibiting excellent agronomic traits,high quality and high yield.Results:The autotetraploid Rehmannia piasezkii(4x=56)was obtained by treating the seeds of Rehmannia piasezkii with 0.1%colchicine.The floral organs of the tetraploid Rehmannia piasezkii were significantly enlarged,the leaf length and leaf width were reduced,and main roots were still not swelled.The seed setting rate of the distant hybridization between tetraploid Rehmannia piasezkii and Rehmannia glutinosa was high,and the germination rate of hybrid seeds reached 58.3%,which effectively overcame the incompatibility of distant hybridization between diploid Rehmannia piasezkii and Rehmannia glutinosa.The somatic chromosome number of the distant hybrid F1 was 56,indica-ted they were allotetraploids.The parent with more main roots and larger diameters among the distant hybrid F1 was selected for back-crossing with the cultivated Rehmannia glutinosa variety,and the backcrossed offspring BC1 F1 was obtained,the morphological observa-tion indicated that more of them had larger tuberous roots than that of F1.And the excellent individual plants in BC1 F1 were selected as parents to continue backcross with cultivars of Rehmannia glutinosa,and their backcross progeny BC2 F1 were obtained,the diameter of tuberous roots was further increased,and the tuberous root diameters of some strains were similar with cultivated Rehmannia glutinosa.Among of them,one backcross offspring line BC2 F1-4(Baizhuangyuan///LY(4x)/85-5//Jinjiu-1)with excellent straits was screened and named as Yunong Dihuang Distant Hybrid 1(YDDH1),its yield per plant was 376.39 g,which was 32.2%higher than that of the control cultivar 85-5.The contents of catalpol and acteoside in the tuberous roots of YDDH1 were 3.90%and 0.052%,which were 1.74 times and 2.05 times higher than control cultivar 85-5,respectively.Conclusion:The autotetraploid of Rehmannia piasezkii is obtained by chromosome doubling,and Through distant hybridization with Rehmannia glutinosa,a new variety with high yield and good quality is obtained,which provides a new idea and method for the variety improvement and germplasm innovation of Rehmannia glutinosa.