Cold Resistance of Parent Varieties, F2 Populations, and F3 Lines of 20 Oat Crosses¹

Abstract

Synopsis Average survivals in lines of crosses among winterhardy, intermediate‐hardy, and spring oat varieties suggest that cold resistance was governed by genes having cumulative effect without important genie interactions. Some crosses showed promise as a source of combinations with more hardiness than the very winter‐hardy variety Wintok.

A Cytological Marker Associated with Winterhardiness in Oat

“…Our results agreed with previous reports that controlled environment freeze tolerance in oat is a quantitative trait with moderate to high heritability (Amirshahi and Patterson, 1956; Muehlbauer et al, 1970). There was significant variation for freeze tolerance among the recombinant inbred lines (Table 1, Fig.…”

“…Only one other report of a bimodal distribution was found in the literature. Amirshahi and Patterson (1956) noted that a normal distribution was typical for segregating progenies in 18 of 20 populations they evaluated in greenhouse tests. One bimodal distribution and one distribution skewed toward lower survival were found in the two remaining populations.…”

Transgressive segregation for frost resistance in hexaploid oats (Avena spp.)

“…The results from the F x experiment generally confirm observations elsewhere (Amirshashi & Patterson, 1956;Pfahler, 1966) that genes determining frost resistance in oats are mainly additive in their effect and do not exhibit large, non-allelic interactions. Although the marked transgression for frost resistance in some crosses in the F 2 experiment could be explained in terms of an accumulation of favourable genes, the absence of a significant Wr, Vr regression and the large SCA effects obtained suggest that non-additive gene action was more important in this subsequent experiment.…”

Moving beyond the Winter Hardiness Plateau in U.S. Oat Germplasm

“…In 20 oat crosses, Amirshahi and Patterson (1956b) found that the cross with the highest heritability (95%) for freezing tolerance and the one with the most lines exceeding the freezing tolerance of Wintok was a cross between Wintok and Norline (an experimental line at the time). Unfortunately, none of those lines were entered into the UOWHN and in storage, the seed quickly lost viability.…”

“…In addition, progress was slowed by the unpredictable occurrence of winters severe enough to kill tender genotypes and damage those of intermediate hardiness (Marshall, 1992). Early evaluations of oat in controlled environment tests designed to supplement field evaluations used juvenile whole‐plant assays (Murphy et al, 1937; Amirshahi and Patterson, 1956a, 1956b). Subsequent improvements in controlled environment techniques involved evaluation of individual lateral crown meristem tissue from which root and shoot regrowth is regenerated (Marshall, 1965).…”