Variation in Oat Kernel Characteristics Within the Panicle¹

Abstract

Oat (Avena sativa L.) investigations are of current interest because of the high quality protein present in the oat groat. In this study, groats were analyzed individually from single panicles selected from three replicates each of ‘Dal,’ ‘Froker,’ and ‘Orbit’ oats grown in the nursery and in the greenhouse. Grain weight, groat weight, groat percent, protein percent, and protein content per groat were determined, and relative position on the panicle was recorded. Within a panicle, groat weight decreased and groat percent increased from primary to secondary to tertiary kernels. Protein percent varied only slightly between primary and secondary groats, but was less in the tertiary of Dal and Froker. About 60% of the total protein was in the primary groats of Dal and Froker. Orbit contained many doubles in which the primary groat was not formed; hence the primary groats contained only about 45% of the total protein. Position of the groat on the oat panicle had an effect on the kernel characteristics. Correlations between groat distance from the panicle base and kernel weight, groat weight, and protein weight were positive and highly significant. Between groat distance from the base and protein percent, the relation was negative and generally highly significant.

Intra-plant variation for progress of cell division in developing oat grains: a preliminary study

“…Furthermore, the position of the panicle with highest cell number in our study (Fig. 1) also tended to produce the largest and heaviest grains in the study of Youngs and Shands (1974). Results from an additional experiment in the greenhouse with the conventional oat cultivar Virma and the naked Rhiannon further supported the finding that secondary grains are consistently lighter (Table 1), also in agreement with our preliminary finding on lower cell number.…”

“…Similarly, growth of primary grain exceeds growth of secondary and tertiary grains (Youngs and Shands 1974, Tibelius and Klinck 1987, Doehlert et al 2002. In fact, the single kernel weight of primary grain seems to be dependent on number of florets in spikelet.…”

“…The position of the spikelet in the panicle and the floret in the spikelet contributes to sink capacity of the grain and determine thereby its potential grain weight (Bonnett 1961a, Youngs and Shands 1974, Housley and Peterson 1982, Tibelius and Klinck 1987Doehlert et al 2002), which is realised at varying degree depending (strongly) on growing conditions at grain-filling period. There are several, possibly interacting, factors contributing to the variation in grain weight.…”

“…Within each spikelet, the primary floret that develops into a primary grain is at more advanced development stage compared to that of secondary florets (Youngs andShands 1974, Tibelius andKlinck 1987). Similarly, growth of primary grain exceeds growth of secondary and tertiary grains (Youngs and Shands 1974, Tibelius and Klinck 1987, Doehlert et al 2002.…”

A bimodal model for oat kernel size distributions

“…Studies (Berry 1920 al. 1952;Youngs and Shands 1974;Doehlert et al 2002) indicated that primary kernels from three-kernel spikelets are larger than primary kernels from two-kernel spikelets. Secondary kernels from three-kernel spikelets are about the same size as primary kernels from one-kernel spikelets, both of which are larger than secondary kernels from two-kernel spikelets.…”