Triploid plants are generally:
Triploids carry three complete sets of chromosomes, 3x, resulting from cross between tetraploid 4x and diploid 2x parents or from failure of reduction in meiosis producing unreduced 2n gamete fertilized by normal n gamete. During prophase I homologous pairing must partition three copies of each chromosome; trivalent formation, or bivalent plus univalent, is common, leading to unbalanced segregation and aneuploid gametes with variable chromosome numbers ranging from n to 2n. Gametes receiving incomplete complement are typically non-viable, pollen abortion high, embryo sac degeneration frequent.
Ref: Marks GE. The sterility of triploids – meiotic basis. Ramsey & Schemske 1998 Ecology of polyploids
