Resistance Identification And Cytogenetic Studies On Wheat-psathyrostachys Huashanica Derived Lines

Fusarium head blight and powdery mildew are the main diseases of wheat,which have been frequent in recent years,which seriously affect the yield and quality of wheat and threaten China's food security.Wild relatives of wheat have many excellent traits and disease resistance genes and are important gene banks for improving wheat.Psathyrostachys huashanica(2n=2x=14,NsNs)is one of the most significant wild relatives of wheat.It is a tertiary gene source of wheat and has many excellent genes for improving common wheat,such as: early maturity and tolerance salt,resistance to barren,drought resistance,etc.,also has excellent traits against a variety of wheat pests and diseases.In order to dig and utilize the germplasm resources of Psathyrostachys huashanica,our group used the hybridization of common wheat 7182 and Psathyrostachys huashanica,and through the immature embryo culture and several times backcrosses,created a series of wheat-psathyrostachys huashanica derived Lines,in this experiment,45 wheat-psathyrostachys huashanica derived Lines were studied,the comprehensive application of evaluation of disease resistance(Fusarium head blight,powdery mildew),cytological identification,genomic in situ hybridization and the investigation agronomic traits to provide available materials wheat resistance breeding.The main results of the experiment are as follows:1.Cytogenetic identification of wheat-psathyrostachys huashanica derived Lines with fusarium head blight resistancetwo moderately resistant lines H-34-8-2-6-1 and H-24-3-1-5-19-1 with resistance to fusarium head bligh were screened out using Artificial inoculation Fusarium graminearum two years.The results of the cytological observation on H-34-8-2-6-1 and H-24-3-1-5-19-1 showed: All the root-tip cells of the two lines was found by cytological examination to have 42 chromosomes(2n=42).By in situ hybridization,H-34-8-2-6-1 was found to have root tip cells with a pair of Ns chromosomes and thus confirmed to be a wheat-Psathyrostachys huashanica substitution line,and H-24-3-1-5-19-1 was found to have root-tip cells with two whole chromosome arms from Psathyrostachys huashanica and thus confirmed to be an wheat-Psathyrostachys huashanica translocation line.The parent wheat 7128 was moderately susceptible and both H-34-8-2-6-1and H-24-3-1-5-19-1 were moderately resistant,so that H-34-8-2-6-1and H-24-3-1-5-19-1 had fusarium head blight resistant genes from Psathyrostachys huashanica and expected to be resistant to wheat fusarium head blight breeding.H-34-8-2-6-1 differed with its parent wheat 7182 in plant height,tiller number per plant,spike length,spike number per plant but insignificantly and had a significantly higher kernel number per spike and a significantly higher kernel-setting percentages than the latter.H-24-3-1-5-19-1 had a significantly lowered plant height compared with its parent common wheat 7182.2.Cytogenetic identification of wheat-psathyrostachys huashanica derived Lines with powdery mildew resistancewheat-psathyrostachys huashanica derived Lines H-3-5-9-3-1 with resistance to powdery mildew was screened out.The results of the cytological observation on H-3-5-9-3-1 showed the root-tip cells was found by cytological examination to have 44 chromosomes(2n=44).By in situ hybridization,H-3-5-9-3-1 was found to the root tip cells with a pair of Ns chromosomes and confirmed to be a wheat-Psathyrostachys huashanica additional line.According to the results of disease resistance identification.The parent wheat 7128 was moderately susceptible and H-3-5-9-3-1 was immune to powdery mildew,so that H-3-5-9-3-1 had powdery mildew resistant genes from Psathyrostachys huashanica.The results of agronomic traits showed that the plant height of H-3-5-9-3-1 was lower than that of the parents,and the difference was significant at the 0.05 and 0.01 levels.The number of tillers increased compared with the parents,and the difference was also significant.The spike length and self-fertility rate were better than that of the parent 7182,and spikelet number per spike and kernel number per spike were close to those of the parent 7182.