On the Natural Hybrid Population of Hemerocallis

Abstract

A large natural hybrid population between Henzerocallis nziddendorfii and IIenzerocallis yezoeitsis occurs a t Otanoshike and its neighborhood in the eastern part of Hokltaido, Japan. This report is the result of a comparative study on external morphology and cytological analysis of the hybrid swarm a t Otanoshilte and of the parental species from various localities in Hoklcaido. The hybrid population a t Otanoshilce represents morphologically a n "introgressive status", and this fact is well ~~nderstood in connection with the ecological condition of the habitat. Among the hybrid swarm intermediate types are dominant. Cytologically, all the material examined was diploid, i.e., it had 2n=22.'Manuscript

Studies on polymorphism of nucleolar chromosomes in Hemerocallis.

“…A comparison of previous records of Hemerocallis (Mookerjea 1956, Kawano 1961, Matsuoka 1972 shows that nucleolar organisers were observed both in the form of secondary constrictions and satellited chromosomes. However, in the present work, the nucleolar or ganisers were always observed in the form of satellites and no taxon was found with secondary constricted chromsomes as found by Mookerjea (1956) and to certain extent by Matsuoka (1972).…”

“…, Stout (1932), Chandler (1940), Sato (1942), Hsu and Liu (1943), Mookerjea (1956), Kawano (1961), Flory (1964), Skolovkskaya (1965Skolovkskaya ( , 1966, Matsuoka (1972), Zadoo et al (1975) and Zadoo and Narain (1984 diploid taxa fall into 11 homomorpic pairs consisting 2 long, 6 medium and 3 short chromosomes. However, this could not be confirmed from the karyotypes of a large number of Hemerocallis taxa.…”

Reproductive isolation on interspecific backcross of F1 pollen to parental species, Hemerocallis fulva and H. citrina (Hemerocallidaceae)

“…We suggest that the death of backcrossed embryos, rather than irregular microsporogenesis of F1 plant or decreased siring ability of F1 pollen, possibly played a more significant role in the seed set reduction. In previous studies of Hemerocallis, high fertility of hybrids between diurnal and nocturnal species has been emphasized (Kawano 1961;Matsuoka and Hotta 1966;Kawano and Noguchi 1973). However, our finding supports that post-pollination (probably post-zygotic) incompatibilities that reduce backcross hybridization did evolve between H. citrina and H. fulva.…”

A new day dawning: Hemerocallis (daylily) as a future model organism

“…There is clear evidence that the recognized species can hybridize in the wild (e.g. Kawano 1961; Hasegawa et al 2006) and in cultivation there appear to be minimal barriers to hybridization between the different species (Stout and Chandler 1933; Stout 1934). However, a level of reproductive isolation in hybrids between Hemerocallis fulva and H. citrina was found in F 1 backcrosses, most likely due to post-zygotic lethality (Yasumoto and Yahara 2008).…”