Inheritance of aposporous apomixis in interspecific hybrids derived fron sexual Paspalum plicatulum and apomictic Paspalum guenoarum

AGUILERA PATRICIA MABEL; FLORENCIA GALDEANO; QUARIN, CAMILO LUIS; ORTIZ JPA; ESPINOZA, FRANCISCO

CROP SCIENCE

CROP SCIENCE SOC AMER

Lugar: Baltimore; Año: 2015 vol. 55 p. 1 - 10

0011-183X

Apomictic Paspalum plicatulum Michx. and P.guenoarum Arechav. are promising candidatesfor forage grass development in tropical regions.From a plant breeding perspective, apomixisprovides a unique mechanism for developingsuperior cultivars and preserving them indefinitely.Therefore, analysis of its inheritance is ofgreat interest in these apomictic species. Theobjective of this work was to analyze the inheritanceand expressivity of apomixis in interspecificfamilies derived from crosses between asexual colchicine-induced plant of P. plicatulumand an apomictic P. guenoarum plant. One F1,one F2, and three backcross (BC) populationswere created. Amplified fragment-length polymorphism(AFLP) markers confirmed the hybridorigin of the F1 descendants. Analysis of thereproductive mode of the F1 by flow cytometryseed screen (FCSS) showed a segregation ratioof 1.6:1 sexual vs. apomictic plants. The sameanalysis in F2 and BC populations showed thatin selfing or crosses involving sexual genotypesall progeny reproduced by sexuality, while BCpopulations involving apomictic hybrids as pollendonors produced offspring that segregatedfor the reproductive mode. Apomixis can betransmitted by pollen from P. guenoarum toother species of the Plicatula group as a simplex(Aaaa) Mendelian dominant factor, and fullsexual reproduction requires the homozygousrecessive (nulliplex) condition (aaaa) for theapomixis determinant. Results provided hereare of interest for breeding apomictic species ofPlicatula and for basic research on the geneticdeterminants of apomixis. Also, the possibilityof creating new apomictic cultivars by traditionalbreeding methods is presented