Detection of zygotic and apomictic embryonic origin in Citrus sinensis Osbeck based on RAPD markers

Purpose: Citrus plant exhibits a unique trait called polyembryony. In open-pollinated plants the pollen source of the plant remains unknown but it is assumed that the apomictic nucellar embryos mimic the genetic architecture of the mother plant. This assumption was exploited in the detection of true-to the type seedlings of polyembryonic Citrus sinensis plants for fruit quality retention and smooth maintenance of the orchards. Research Method: The randomly amplified polymorphic DNA (RAPD) technique was employed to distinguish nucellar and zygotic seedlings obtained from a selected Citrus sinensis plant marked in South 24- Parganas district of state of West Bengal in India. The embryos were extracted from a fruit and seedlings were raised in poly-house. To identify DNA marker for tracing the embryonic origin, ten vigorous seedlings marked in poly-house were used for RAPD analysis. DNA was extracted from three-month-old seedlings along with the mother plant and RAPD analysis was performed with 25 arbitrary decamer primers with a negative control. Findings: Four decamer primers OPQ15, OPAH02, OPAA02 and OPA11 were able to differentiate the sexual seedlings from the apomictic nucellar types. The total study took 48 hours for tracing the embryonic origin of the seedlings. Research limitations: This study could be extended with inclusion of more primers and screening of more fruits from diverse locations of India. Originality/Value: This process could act as a fast technique for preliminary identification of true-to the-type plants for quality control of Citrus fruit industry and sustainable nursery management.