Compositional stability of an oat multiline

Abstract

Mixtures of genotypes are frequently unstable in composition when propagated over successive generations . This study was designed to test whether a multiline cultivar of oats (Avena sativa L .) created to control crown rust disease (caused by Puccinia coronata CDA .) would reflect differential near-isogenic line survivals when propagated under conditions of either presence or absence of rust . An oat multiline cultivar synthesized from near-isogenic lines that had different genes for resistance to crown rust was propagated under rust-free and rust epiphytotic conditions for four successive generations . In the rust-free environment, one near-isogenic line, CI 9192, which was inferior in yielding ability, was reduced significantly from 20% to 10% of the mixture, and CI 9184, which has no yield deviation from normal, increased from 20% to 38% . The other three near-isogenic lines were stable at about 20%. Also, in the rust line of descent, CI 9192 and CI 9184, respectively, decreased and increased significantly .Our results have implications with respect to seed production practices for multiline cultivars; they also raise the question of whether a multiline is stable enough in composition to be called a cultivar .

Host frequency and density effects on powdery mildew and yield in mixtures of barley cultivars

“…The initial and harvested proportions of the cultivars changed only little, indicating that competitive interactions among the three cultivars were similar. This is in contrast to other studies with barley (Harlan & Martini, 1938;Blijenburg & Sneep, 1975), oats (Murphy et al, 1982), and wheat (Finckh & Mundt, 1992a), where initial and harvested frequencies usually varied greatly.…”

Functional agrobiodiversity and agroecosystem services in sustainable wheat production. A review

“…The first is the effect of plant-plant interactions within the population on evolutionary dynamics and its impact on population performance, already discussed in Phillips and Wolfe (2005). On this subject, Döring et al (2011) raised three points: (a) the evolutionary advantage of genotypes producing more and smaller kernels over those producing less and larger kernels, (b) a possible population drift towards the prevalence of highly competitive, but agronomically poor genotypes, as already pointed out by Murphy et al (1982), and (c) a possible trade-off between yield increase and end-use quality, e.g. grain protein content.…”

“…the ability to exactly predict the identity of the material that we are growing. Murphy et al (1982) addressed the problem of the compositional stability of multiline cultivars, trying to understand whether these seeds would better be considered as cultivars or blends. Multilines are basically mixtures of near-isogenic, bulk-reproduced lines.…”

Interplant competition among oat and barley varieties and isolines

“…In all cases the best available copy has been filmed. Murphy et al (1982) reported that the isoline composition of a multiline variety of oats did not remain con stant over a four-year period that the multiline was propa gated. The composition changed similarly and significantly when the multiline was grown in a rust-free and in a rustepidemic environment, so the authors concluded that the isolines possessed differing competitive abilities that might be related to expression of certain agronomic trait(s).…”

“…The composition changed similarly and significantly when the multiline was grown in a rust-free and in a rustepidemic environment, so the authors concluded that the isolines possessed differing competitive abilities that might be related to expression of certain agronomic trait(s). As a follow-up to this study, I conducted experiments (a) to de termine whether differing competitive abilities could be measured among the isolines used in the Murphy et al (1982) study, among oat isolines in the Multiline E series (Frey and Browning, 1976b), among five oat varieties, and among oat and barley varieties and (b) to assess whether specific agronomic traits could be associated with differences in competitive ability.…”