Nature and Inheritance of Apomixis in Bothriochloa and Dichanthium

Breeding Panicum maximum in Brazil. 1. Genetic resources, modes of reproduction and breeding procedures

“…Sexual × apomict crosses made in Japan, using sexual tetraploids which also originated from natural diploids, gave segregations in agreement with this model (Nakajima & Mochizuki, 1981). Similar hypotheses of a simple genetic control for apomixis have already been discussed for the BothriochloaDichanthium complex (Harlan et al, 1964), Cenchrus ciliaris (Taliaferro & Bashaw, 1966;Read & Bashaw, 1969), and Eragrostis curvula (Voigt & Bashaw, 1972). More recently, preliminary data 109 from interspecific hybridizations in Brachiaria (Ndikumana, 1985), suggested a similar simple inheritance.…”

Polyploidy and Apomixis in <i>Apluda mutica</i> L. var. <i>aristata</i> (L.) Pilger

“…However, a more reasonable conclusion seems to be that the aposporic embryo sacs, due to their precocious development, compete with the normal sexual sacs resulting in exclusively maternal progenies. In their studies of apomixis in Bothriochloa and Dichanthium, Harlan et al (1964) have also obtained a similar result. The pro portion of sexually obtained offspring is always less than the proportion of the sexual sacs.…”

“…Thus "facultative apomicts have exploited an extremely effective solution that enables them to store interspecific variability and to nevertheless remain constant for ages" (Clausen 1954). According to Harlan and Celarier (1961), the net effect of apomixis is as a long range binding force permitting gene exchange among widely divergent materials and knitting together large groups which would drift apart if sexual reproduction alone were operating. From the few collections included in this study, it is not possible to say whether in the complex of Apluda mutica the apomictic reproduction conferred any adaptive advantage to the polyploids.…”

Fertility of Brachiaria ruziziensis in interspecific crosses with Brachiaria decumbens and Brachiaria brizantha: meiotic behaviour, pollen viability and seed set

“…A simple genetic determinism of apomixis (mono-or oligogenic) has been proposed for other grass species of the tribes Paniceae and Andropogoneae (Harlan et al, 1964;Taliafero & Bashaw, 1966;Bashaw, 1980;Savidan, 1982). Moreover, several studies have demonstrated the possibility of obtaining F~ apomictic hybrids by crossing sexual and apomictic species (Bashaw, 1980;Dujardin & Hanna, 1985;Hanna & Dujardin, 1986;Dujardin & Hanna, 1988;Weber & Campell, 1989).…”