小麦与黑麦属间杂种的染色体自然加倍的研究

NATURAL DOUBLING OF CHROMOSOMES OF HYBRIDS BETWEEN WHEAT AND RYE

分别以小麦属６个种的变种或品种共９个供试材料为母本，２个黑麦种为父本进行杂交。只有Ｓｔｅｗａｒｔｄｕｒｕｍ小麦与２个黑麦种杂交后，才得到Ｆ_１种子，说明染色体的自然加倍需要一定的遗传背景。对这２个Ｆ_１代花粉母细胞减数分裂所形成配子的观察表明，配子形成途径的不同，使Ｆ_２出现了双二倍体和部分双二倍体的差异。

Using nine varieties of wheat(Triticum)as female and two varieties of rye (Secale)as male, we made these crosses separately,and obtained hybrid plants from some crosses by embryo cultures.However, the F_1's seeds were obtained only from the crosses of the two ryes with Stewart durum wheat(T. durum cv.Stewart). It is shown that natural doubling of chromosomes needs specifically genetic background(s).In Stewart×S. cereale the unreduced gametes were produced from pollen mother cells,and these F_1 hybrids were amphidiploids. The process of gametic production is similar to that of normal somatic division.Although the process of gametic formation was normal in Stewart×S.montanum,the numbers of chromosome of formed gametes were l～2l respectively. Thus,in the F_1's seeds from this cross there were both amphidiploids and partial amphidiploids. Hence there are differences between Stewart×S. cereale and Stewart×S. montanum on the formation of amphidiploid.