TECHNOLOGY OF CEREALS Reproductive features of grasses 1. All stems and branches normally form terminal inforescences 2. Flowers are produced in spikelets 3. Each flower is enclosed between two bracts the lemma and palea (pales or flowering 4. At the base of each spikelet are two glumes (empty or sterile glumes) All cereal inflorescences are branched structures but the type of branching varies. The loose spreading structure found in oats is known as a panicle(Fig. 2.3) The main axis of the panicle, the peduncle bears several extended branches on which the spikelets are attached through short stalks or edicels. Within the spikelet forets alternate (Fig. 2. 4); the two closest to the base are similar in size but forets become progressively smaller towards the Each floret(Fig. 2.5)contains the female organs, a carpel containing a single ovule, with its stigma; and the male parts three stamens each consisting of filament and anther pollen released from the anthers, which split when ripe, FlG 2.3 The oat panicle Reproduced from Poehlman(1987) another plant. The elaborate feathery style has an extensive sticky surface well suited to intercept ing wind-borne pollen. Before the anthers mature udimentary tertiary floret the time of fowering or'anthesis'the pales are foret g corday pened primary floret forced open by the expansion of organs called Palea Lemmo lodicules at their base (lodicules swell as a result of an influx of water). The filaments of the stamens rapidly extend, projecting the opening others outside the pales, allowing the pollen to be shed onto the wind lets contain only one floret. Glumes are mostly insignificant small scales. Rice florets are unlike those of other cereals in having six stamens. Fig 26) In sorghum the situation is complex: infore- scences are panicles but they may be compact or Glume open(Hulse et aL., 1980). Spikelets occur in pairs one is sessile and the other borne on a short FIG 2.4 Spikelet of oat Reproduced from Poehlman(1987) pedicel. The sessile spikelet contains two florets, by courtesy of Avi Publishers, New York30 TECHNOLOGY OF CEREALS Reproductive features of grasses 1. All stems and branches normally form terminal 2. Flowers are produced in spikelets. 3. Each flower is enclosed between two bracts, the lemma and palea (pales or flowering glumes). 4. At the base of each spikelet are two glumes (empty or sterile glumes). All cereal inflorescences are branched structures but the type of branching varies. The loose spreading structure found in oats is known as a panicle (Fig. 2.3). The main axis of the panicle, the peduncle, bears several extended branches on which the spikelets are attached through short stalks or pedicels. Within the spikelet florets alternate (Fig. 2.4); the two closest to the base are similar in size but florets become progressively smaller towards the tip. Each floret (Fig. 2.5) contains the female organs, a carpel containing a single ovule, with its stigma; and the male parts, three stamens, each consisting of filament and anther. Pollen released from the anthers, which split when ripe, is transferred by wind to the receptive stigma on another plant. The elaborate feathery style has an extensive sticky surface well suited to intercept￾ing wind-borne pollen. Before the anthers mature, the time of flowering or ‘anthesis’ the pales are forced open by the expansion of organs called lodicules at their base (lodicules swell as a result of an influx of water). The filaments of the stamens rapidly extend, projecting the opening anthers outside the pales, allowing the pollen to be shed onto the wind. Rice inflorescences are also panicles but spike￾lets contain only one floret. Glumes are mostly insignificant small scales. Rice florets are unlike those of other cereals in having six stamens. (Fig. 2.6) In sorghum the situation is complex: inflore￾scences are panicles but they may be compact or open (Hulse et al., 1980). Spikelets occur in pairs, One is sessi1e and the Other borne On a short pedicel. The sessile spikelet contains two florets, inflorescences. FIG 2.3 The oat panicle. Reproduced from Poehlman (1987) by courtesy of Avi publishers, New yo&. Rudimentary tertiary floret they remain enclosed between the pales but at ned primary floret f‘oret FIG 2.4 Spikelet of oat. Reproduced from Poehlman (1987) by courtesy of Avi Publishers, New York