Training Manual Development Of Cultivars And Seed ... - icrisat

Stem. The pearl millet stem or culm consists of nodes and internodes. The solid stem is thick at the
base. The nodes are slightly swollen, and axillary buds are present in shallow grooves at the nodes. The
nodes are hairy as well as glabrous with a gradual increase in hairiness from the base to the apex. The
lower internodes are largely covered by the sheaths of the leaves, while the upper internodes are only
partly covered. The upper internodes are more elongated than the lower ones. The height of the stem
ranges from 0.5 m to 3.0 m.
Tillers. The development of tillers starts from the lower nodes of the stem 3-5 weeks after emergence.
These are called primary tillers. The secondary (axillary) tillers develop from the axillary buds at the upper
nodes, usually after completion of flowering on the main stem.
Leaves. The leaves are arranged alternately in two vertical rows on the culm. They are linear in shape
comprising of a leaf sheath and a blade. The leaf sheaths are light green or purple and envelop the stem
slightly above the nodes. The leaf sheaths overlap at the base of the stem but are open in the upper
portion. The leaf sheath is glabrous and grooved. Ligules are present at the junction of the leaf blade and
the leaf sheath. They are membranous, hairy, 4-5 mm long, and clasp the stem.
The leaf blade is lanceolate, 90-100 cm long and 5-8 cm wide, with a pointed tip. The midrib is
dull green. Auricles are present at the base of the leaf blade. The upper leaf surface is scarbid and hairy,
while the lower one is smooth and glabrous.
The leaf area of pearl millet is calculated by measuring the length and the width (at the broadest
point) as suggested by Singh et al. (1970).
Reproductive System
Leaf area = Leaf length (cm) x Leaf width (cm) x 0.7236
The shoot apex is transformed into a reproductive apex (Fig. 4) with the formation of the panicle
meristem. The panicle meristem is bulbous, with a constriction at its base. It develops tunica and corpus
layers in the inflorescence axis. These cells (tunica and corpus) are eumeristematic. The different floral
organs develop from the apex. The organogenesis and maturation of organs in the spikelet apex are
acropetal (Gill 1991).
Inflorescence. The pearl millet inflorescence is a false spike, ranging from 5 to 150 cm in length and
1 to 5 cm in diameter. The panicle is terminal, varying in shape from cylindrical to candle-shaped. The
spike consists of a central rachis which is closely packed with fascicles. Each fascicle consists of one
or more spikelets and a whorl of 70-80 bristles. The tip of the spike has only a single spikelet. The
bristles may be free or united to form an involucre. About 10-15 bristles in the upper whorls are longer
than those in the lower ones. The bristles are broader at the base and narrower at the tip. They are
scarbid and green or purple. An inflorescence may contain 870-3000 spikelets with an average of 1600
(Khairwal et al. 1990).
Spikelets. The spikelets are small, lanceolate, and acute. Each spikelet consists of two glumes, one
outer and one inner. The outer glume is broad, short, membranous, and truncate. The inner glume is
broad and half the size of the spikelet. Between the two glumes, there are (two) florets. The lower floret
is staminate and the upper floret is hermaphrodite (Fig. 5). Spikelets are generally bifloret but can
sometimes be trifloret or tetrafloret; in rare instances, more than four florets are present (Maiti and Bisen
1979).
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