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The Karyotype Analysis of Zea Species and the Genetic Studies of the Aneuploid Hybrid Involving Maize and Zea Perennis

Author: YangXiuYan
Tutor: RongTingZhao；TangQiLin
School: Sichuan Agricultural University
Course: Crop Genetics and Breeding
Keywords: Corn Tetraploid perennial teosinte Karyotype Aneuploidy Genomic in situ hybridization
CLC: S513
Type: Master's thesis
Year: 2010
Downloads: 48
Quote: 1
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Abstract

The this study Zea today classification Chu grasses and corn karyotype research; Meanwhile, corn and tetraploid perennial teosinte hybrid synthesis of a specific aneuploidy material (MDT) system morphology, chromosome composition and hybridization studies and trials, the main results are as follows: 1. Zea of ??teosinte (sub) species and maize cytological study results show that the various kinds of Zea and subspecies of chromosome number in addition to the tetraploid perennial big Chu grasses 2n = 4x = 40, the number of chromosomes of other species (subspecies) are 2n = 2x = 20. Zea Guinea genus and species of the subgenus chromosome karyotype small structural differences, the various species and subspecies of chromosomes are metacentric and nearly metacentric chromosome composition, with the body are all located on the short arm; addition to the tetraploid perennial the Chu grasses with the two pairs with the in vitro, with the body of other species (subspecies) with one pairs with the body, with the body of which corn metacentric chromosome, teosinte are located near middle The metacentric chromosome upper. The karyotype classification on four kinds of lush subgenus are the 2A and corn subgenus belong to the type \2 on the tetraploid perennial Chu grass nuclear type. System. The results indicate that the species chromosome number of 2n = 40 karyotype formula 2n = 4x = 40 = 18m 22sm (4sat), karyotype type 2B-type, on chromosome 11 and 12 each have a pair with the body, chromosome relative length ratio between the longest and shortest 1.94 arm ratio gt; chromosome ratio of 30%, for 62.46 AS.K. 2B type diploid karyotype perennial teosinte compared between the two nuclear-type parameter differences, indicating that a tetraploid perennial Chu grasses and diploid perennial the big the Chu grass is two separate species , does not support the tetraploid perennial large Chu grasses from diploid perennial big Chu grasses evolved view. Corn on the synthesis of a specific and tetraploid perennial teosinte aneuploidy material (MDT) system morphology, chromosome composition as well as hybrid and other studies have shown that: (1) MDT for perennial growth period long, stout stems, vigorous tillering, luxuriant growth of plants combined with corn and tetraploid perennial teosinte good traits; pollen grains are highly sterile, Ear part fertile. Cytological Identification (2) MDT results show that the apical cell chromosome number 39, aneuploid; pollen mother cells in meiosis diakinesis configuration performance more complex the divalent vitro chromosome pairing normal univalent or multivalent body of the high frequency, almost every cell, an average of in Statistics 135 cells, diakinesis chromosome configuration is 2.93 Ⅳ 2.74 Ⅲ 9.36 Ⅱ 3.08 Ⅰ: meiotic metaphase I to later various periods observed abnormal chromosomal abnormalities distribution and uneven separation occurred, final Ⅱ multi-pole separation. (3) The total corn genomic DNA as a probe to the genetic composition of the monochrome genomic in situ hybridization analysis of MDT results show that 9 yellow hybridization signal chromosome maize chromosomes, the 30 chromosomes of the red fluorescent signal from the tetraploid perennial teosinte. (4) of MDT and corn and tetraploid perennial teosinte backcross progeny preliminary analysis of corn the MDT and corn hybrids plant traits tend, their number of chromosomes 29, 30, 31, 30 frequency high pollen fertility rates, seed rate, rows per ear traits compared with MDT has gradually improved trends; MDT tetraploid perennial teosinte hybrid progenies phenotypes to MDT similar, but the number of tillers than MDT reduced plant growth lush holding green long period, to generate new tillers have the whole growth cycle, male and female spike characteristics with MDT approximate their somatic chromosome numbers higher frequency of 39 or 40. (5) This created a specific perennial aneuploid material transfer as a breakthrough aneuploid tetraploid perennial teosinte germplasm novel germplasm resources to build a corn (or tetraploid perennial teosinte) new chromosome family has opened up new avenues.

The Karyotype Analysis of Zea Species and the Genetic Studies of the Aneuploid Hybrid Involving Maize and Zea Perennis

Abstract

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