Leaf Volatiles as a Biomarker for Identification of Nucellar and Zygotic Seedlings in Polyembryonic Mango (Mangifera Indica L.) Genotypes

Mango, one of the most important fruit crops in the world, has both monoembryonic and polyembryonic varieties. The nucellar seedlings from polyembryonic varieties are exactly the same as the mother plant, while zygotic seedlings vary due to fertilization of a zygote by the pollen parent. However, there are no reliable methods that include the molecular tools for the identification of nucellar seedlings. Therefore, leaf volatiles of polyembryonic and monoembryonic varieties were used for comparison with that of their respective seedlings. The leaf volatile constituents were analyzed using gas chromatography–mass spectrometry (GC-MS) by headspace solid-phase microextraction technique (HS-SPME). Volatile constituents of the last emerging seedling from a stone were different from those of the respective mother plant, while those of the remaining seedlings were exactly the same as each other and as the respective mother plant in polyembryonic genotypes, namely ‘Chengavarkai’, ‘Turpentine’ and ‘Gomavu’. In the case of monoembryonic cv. ‘Totapuri’, the volatile profile of the mother plant was different from all its seedlings. Thus, the last emerging and weakest seedling is zygotic, while the rest are nucellar in polyembryonic mango genotypes. Volatile profiling is hence an effective biomarker to distinguish zygotic from nucellar seedlings in mango.