Research On Chromosome Inheritance And Application Value Of The Progenies Of Saccharum Officinarum And Erianthus Rockii

Sugarcane（Saccharum spp.）is an important sugar crop and a potential resource for energy and animal feed development.Due to the long-term hybridization between varieties in the process of sugarcane breeding,sugarcane is closely related,which makes it difficult to make a great background the traits of the bred sugarcane.Therefore,in order to improve the yield and resistance of sugarcane and solve the breeding problems such as the narrow genetic basis of sugarcane,Erianthus rockii have used by breeders as an excellent resistance starting parent material for basic breeding and improvement of sugarcane.Erianthus rockii is a related germplasm of sugarcane with excellent stress resistance such as drought resistance and rust resistance.In order to make better use of the Erianthus rockii and to gain an in-depth understanding of the genetic information of hybrization between sugarcane and Erianthus rockii,the following studies were carried out.Firstly,the F₁,BC₁ and BC₂ between sugarcane and Erianthus rockii were identified by Genomic in situ Hybridization（GISH）;To understand the authenticity and chromosome composition of the hybrid progeny,and to verify the chromosome transmission behavior between he Sugarcane and the Erianthus rockii in the distant hybridization.Secondly,evaluate the rust resistance and drought resistance of hybrid progenies of Erianthus rockii,and screen resistant sugarcane materials to provid excellent resistance sources for breeding rust resistant and drought-resistant varieties.Finally,the agronomic characters of the progeny materials to understand the changes of agronomic characters in the process of nobility of Erianthus rockii.These will provide reference for the breeding and germplasm resource utilization of the hybrid progeny of sugarcane and its related genus Erianthus rockii.The main results are as follows:1.Chromosome genetic pattern of F₁,BC₁ and BC₂between sugarcane and Erianthus rockii and chromosome distribution of Erianthus rockiiThe results of GISH identification showed that in F₁ population,except 17-102,all the other 13 materials contained Erianthus rockii chromosomes,indicating that these 13 materials were real progenies of,and the number of hromosomes of 17-154 and 17-134 are 14,and the other11 materials are 15.Thus the inheritance pattern is n+n.All the14 BC₁materials contain Erianthus rockii chromosomes,indicating that these 14materials are all true hybrid progenies,in these BC₁material,the number of Erianthus rockii chromosomes of clone18-8 is 13,that of clone18-72 is 14,and the other 12 materials are 15,therefor the chromosome inheritance pattern is n+2n.Both of the two BC₂materials contain 8 Erianthus rockii chromosomes,and the chromosome inheritance pattern is n+n.2.Identification of rust resistance of sugarcane and F₁and BC₁ of Erianthus rockiiThe clones of F₁、BC₁ of Erianthus rockii were inoculated by spraying with brown rust.The results showed that17 of the 25 identified materials showed high resistance（68%）,4 showed disease resistance（16%）,2 showed medium resistance（8%）,and 2 showed medium susceptibility（8%）.PCR detection of Bru1 gene showed that 8 of 12materials in F₁ contained Bru1 gene,and 11 of 13 materials in BC₁contained Bru1 gene.It indicated that the Bru1 gene of Erianthus rocki could be easily inherited to their offspring,and the resistance was easy to be inherited to the offspring.3.Identification of drought resistance of sugarcane and Erianthus rockii F₁and BC₁The results showed that 17-109 and 17-157 had higher average green leaf rate and less damage by drought;ROC22,17-115 and 17-157 showed less loss to plant height and less damage by drought.Through the comprehensive evaluation of drought resistance,the order of drought resistance of the eight materials from strong to weak is 17-157>ROC22（CK）>17-109>17-115,18-19>18-74>18-66>ROC16（CK）.It shows that 17-157 has the strongest drought resistance and 18-66 has the weakest drought resistance among the progenies of Erianthus rockii.4.The main agronomic characters of sugarcane and F₁ and BC₁ were investigatedIn this study,the plant height,stem diameter,brix and other main characters of the progeny clones of Erianthus rockii were measured.From the four characters of Erianthus rockii F₁,the average values of tiller and brix were higher than the average values of parents,and the average performance was slightly higher than that of middle parents.Similarly,the average values of tiller,plant height and Brix of Erianthus rockii BC₁also slightly exceed the middle parent value,and the agronomic characters of Erianthus rockii BC₁ tend to be close to modern sugarcane.The comprehensive characters of Erianthus rockii 17-115 and 18-73 in F₁and BC₁ progeny materials are better than other progenies,which can be further used as parents.