Morphology And Molecular Cytogenetics Of The BC₂ And BC₁F₁ Progenies Derived From Triticum Aestivum×Psathyrostachys Huashanica

Wheat is one of the most important food crops in the word and becoming increasingly important in agriculture.In the modern agricultural system,the narrow of genetic base,small of genetic difference,seriously loss of genetic diversity,fragile of biological and non-biological environmental stress in bread wheat(Triticum aestivum L.) limit seriously breed wheat's yield and quality.Many wild species of Triticeae contain excellent genes,such as resistance to disease,resistance to insect and resilience,and they are important resources for wheat improvement.Psathyrostachys huashanica Keng ex Kuo(2n=2x=14,NsNs) is a species of Psathyrostachys Nevski,which is a small genus in the tribe Triticeae(Poaceae). Compared with the other Psathyrostachys species,P.huashanica has a very restricted disjunct distribution,and occurs only in Huashan Pass in Qinling Mountains,Shanxi Province,China.It has been attracted special attention for wheat breeders due to its dwarfing, prematurity,drought and salinity tolerance as well as resistance to disease such as stripe rust, wheat take-all fungus and scab and other excellent features.Therefore,it is a potentially useful germplasm for wheat improvement.The objective of this study is to detect the Psathyrostachys huashanica chromatin of the BC₂ and BC₁F₁ progenies derived from Triticum aestivum×p.huashanica by morphological,cytogenetic,molecular cytogenetics and biochemical techniques.The results are as follows:1.Morphological study showed that every agronomic trait's coefficient of variation of mature plants is greater than their parents,and the coefficient of variation of tillers is largest.Most plants in the tillering,length of spike and ears have shown superior to CSph2b.There were potential of specific plant resources.Some plants were high resistance to strip rust or immune to scab.2.The somatic chromosome number varied from 2n=42 to 2n=52 among 978 BC₂ and BC₁F₁ plants observed.The plants with 2n=45 accounted for 20.6%,while the plants with 2n=51 was only 0.6%.The chromosome number of BC₂ varied from 2n=42 to 2n=50,and the plants with 2n=45 accounted for 21.2%.The chromosome number of BC₁F₁ varied from 2n=42 to 2n=52,and the plants with 2n=45 accounted for 20.2%.3.In the plants with different number of chromosomes,the average univalents of per cell were difference,and varied from 0.06-6.94.The average univalents of per cell in the plants with 2n=42,43 and 44 varied from 0.57-4.87,1.42-3.36 and 0.06-3.22,respectively. Trivalents,quadrivalents,lagging chromosomes,trinulceate cells,micronuclei and chromosome bridges have been observed in the most plants.4.The results of sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) revealed that(1) B113(2n=44) possessed five High-molecular-weight glutenin subunits(HMW-GSs),which contained one P huashanica characteristics band;(2) D163(2n=43) with five HMW-GSs,among them,two novel bands appeared but the 1By8 subunit disappeared;(3) D72(2n=43) with five HMW-GSs,among them,the 1Dx2 subunit disappeared,and two novel bands appeared;(4) D12(2n=44) with six HMW-GSs,one from P.huashanica,and a novel band appeared5.The plant D72 with 2n=43 added one N₆^h chromosome of P.huashanica.H33 with 2n=44 added two N₃^h chromosomes of P huashanica.L8 with 2n=44 added one N₃^h chromosome and one N₅^h chromosome of P.huashanica.6.The plant D182 with 2n=42,the P.huashanica chromosome segment was detected in the end of the long arm of chromosome by GISH.D72 with 2n=43,one P.huashanica chromosome was detected by GISH.H33 and L8 with 2n=44,two P huashanica chromosomes were detected by GISH.