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对加拿大披碱草与老芒麦种间杂种F1的形态学和细胞学特征进行研究。形态学观察结果表明,杂种F1的穗形介于双亲之间,呈半弯曲形,其母本加拿大披碱草植株浅绿色,茎粗糙,穗粗大而弯曲,每节2～3小穗,颖和外稃粗糙具短毛。父本老芒麦全株粉绿色,穗状花序疏松下垂,每节2小穗,每小穗3～5小花。杂种F1植株灰绿色,粗糙,外稃和颖具柔毛,偏向母本加拿大披碱草。加拿大披碱草染色体都是由中部着丝粒染色体组成,染色体相对长度范围在10～4.65,最长染色体与最短染色体之比为2.2:1,臂比介于1.14～1.35。染色体核型公式为2n=4x=28m,属于1A类型。老芒麦染色体核型公式为2n=4x=22m+6sm,属于1B型;F1的染色体数为2n=4x=28,染色体相对长度的变异范围在8.83～4.42,臂比值变化在1.00～3.33。其中,第1、5、7、9、11、12、13、14对染色体为正中着丝粒(M)染色体,第3对为近端着丝粒染色体,剩下的染色体为中部着丝粒染色体,其中,正中着丝粒(M)染色体的数目增加,近中着丝粒染色体(sm)已不存在。L/S恰好为2:1,核型类型为2B。核型公式为2n=4x=16M+10m+2st。通过形态学和染色体的核型分析可以初步确定,F1是真杂种;但杂种F1不结实。加拿大披碱草和老芒麦含有落后染色体细胞的频率较低,分别为0.96%和2.76%;F1减数分裂后期染色体的分配出现了异常行为,染色体有落后现象,落后的染色体细胞频率较高,达87.37%,F1在减数分裂中期一部分染色体也能配对形成二价体,但染色体配对杂乱无章,棒状二价体占多数,环状二价体较少,且出现多价体。
Morphological and cytological characteristics of interspecific hybrid F1 between Elymus dahuricus and E. przewalskii were studied. Morphological observation showed that the spike shape of hybrid F1 was intermediate between parents and showed a semi-curved shape. The maternal Canadian Elymus plants were light green with rough stems and large and curved spikes. Each spike had 2-3 spikelets And nephew rough with short hairs. The male parent Simao whole plant pink green, sparse loose spikes, each 2 spikelets per spike 3 to 5 florets. Hybrid F1 plants are gray-green, rough, lemmas and pilose, favoring the female Canadian Elymus. Elymus chinensis chromosomes are composed of centromeric chromosomes, the relative length of chromosomes in the range of 10 ~ 4.65, the longest chromosome and the shortest chromosome ratio of 2.2: 1, arm ratio of 1.14 ~ 1.35. Chromosome karyotype formula 2n = 4x = 28m, belonging to 1A type. The karyotype of S. mandshurica was 2n = 4x = 22m + 6sm and belonged to type 1B. The chromosome number of F1 was 2n = 4x = 28, the relative length of chromosome ranged from 8.83 to 4.42, and the arm ratio changed from 1.00 to 3.33. Among them, the 1st, 5th, 7th, 9th, 11th, 12th, 13th and 14th pairs of chromosomes are the middle centromere (M) chromosomes, the third pair is the proximal centromere chromosomes, and the remaining chromosomes are the centromere Chromosomes, in which the median number of centromere (M) chromosomes increased, and the near-meiosis chromosome (sm) no longer existed. The L / S is exactly 2: 1 and the karyotype is 2B. The karyotype formula is 2n = 4x = 16M + 10m + 2st. Morphology and chromosome karyotype analysis can be initially identified F1 is true hybrids; hybrid F1 is not strong. Canadian Elymus and Siberian Propolis have a lower frequency of lagging chromosomes of 0.96% and 2.76%, respectively. Aberrant behavior of chromosomal distribution occurs in the late stage of meiosis of F1, and the chromosomes lag behind with higher frequency of lagging chromosomal cells , Up to 87.37%, F1 in the metaphase metaphase chromosomes can also be paired to form a bivalent body, but the chromosome pairing disorderly, rod-shaped bivalent accounted for the majority of annular bivalents less polyvalent body.