Karyotype and SSR Analysis between Inbredline K169 and Its Distant Derived Lines from Zea mexicana schard×K169 Sexual Incompatibility between Maize and Its Wild Relatives Tripsacum L. and Coix L. Preliminary Study of Trait Variations in the Progenies of Inbred Maize Lines×Zea luxurians Response of Gas Exchange, Chlorophyll a Fluorescence and Anti-oxidation Enzymes Activities to Osmotic Stress in an Upland Rice Progeny YF2-1 Derived from Oryza sativa × Echinochloa caudata Study on Sorghum sudanese × S.propinguum interspecies hybridization