Genetic stability analyses in inbred lines derived from distant hybrid parthenocarpy with giemsa C - Banding markers

Giemsa C - banding patterns of 6 inbred lines derived from the parthenocarpic progenies of a backcrossed distant hybrid [(Zi-330 x DP) BC₁] and their parents were investigated in this paper. The results indicated that great variations (including changes of C - bands' number and distribution in the genome, and /or C - bands heterozygosity) existed in the patterns of C - banding constitutive heterochromatin of these 6 lines. The variations were found not only in 3 inbred lines with unstable characters but also in 3 inbred lines with stable characters. This may be due to that germplasm introgression of diploperennial teosinte (DP), one of the distant cross parents, affected the genetic balance and then this brought about chromosomal structure arrangement and / or chromatin constituent changes. These changes were directly correlated with abnormal pairing in meiosis between duplicated chromosome segments presented abundantly in maize genome. The authors proposed that heterochromatin change (s) in genome might play an important role in balancing the germplasms between maize and its distant relative after cross and parthenocarpy. Observation in this paper may be beneficial for understanding the basis in plant parthenogenesis and its values in maize breeding.