Megasporogenesis and Development of Female Gametophyte in the Apomictic Monosomic Addition Line M14 of Beta corolliflora in Sugar Beet

The megasporogenesis and development of female gametophyte were studied by paraffin sections in line M14,a chromosome 9 monosomic addition line of Beta corolliflora Zoss.in sugar beet,in which revealed that the egg cell could been produced through diplospory or sexuality.The results are as follows:sexuality is of Polygonum-type,and diplospory is of two types,Allium odorum-type and Antennatia-type in M14.The megasporocyte of Allium odorum-type and Antennatia-type turn into a mature diplosporous female gametophyte.The Megasporocyte Polygonum-type turns into a mature monoplontic female gametophyte.Compared with the sexual female gametophyte,bradygenesis and abortion can be frequently observed during the development of diplosporous female gametophyte.Only 25% of them are normal.The characteristic of diplosporous reproduction is discussed.