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

Reproductive Biology of Pearl Millet
Faujdar Singh
Pearl millet belongs to the family Poaceae, subfamily Panicoideae, tribe Paniceae, subtribe Panicinae,
genus Pennisetum, and section Penicillaria (Pernes et al. 1984). Harlan (1971) has reported that the
center of origin of pearl millet is in the Sahelian zone in Africa between western Sudan and Senegal.
Pearl millet has also been described earlier as Pennisetum typhoides (Burm) Stapf and Hubb.,
and Pennisetum americanum (L.) Leeke. It is primarily cultivated for grain purposes in India, New
Mexico, Southeast Asia, and the West, East, and Southern African countries, and in the United States
of America for fodder. Pearl millet is an annual plant, which grows well on light-textured soil under low
moisture conditions. This chapter deals with the pearl millet plant and its reproductive system.
Germination and Seedling Development
Pearl millet seeds germinate in 3-5 days when sown at a depth of 3-5 cm in the soil with sufficient
moisture and at optimum temperature. Germination begins with the absorption of moisture by the seed
due to which it swells and ruptures the seed coat. A small coleoptile and a radicle emerge from the seed
(Fig. 1). The coleoptile emerges out of the ground, and the first leaf develops from its tip.
Pearson (1975) reported that final germination of pearl millet was independent of day/night
temperatures when tested in a range of 15/10°C to 33/28°C. However, the rate of germination and
emergence, seedling survival, leaf-area expansion, and dry-matter accumulation were highest at 33/28°C.
Root System
The pearl millet root system consists of three types of roots: primary, secondary, and brace roots (Fig.
2).
P r i m a r y r o o t s . The radicle roots or seminal roots after germination develop into the primary roots. These
roots continue to develop for 45-60 days.
S e c o n d a r y r o o t s . These are also known as adventitious roots. The first pair of secondary roots develops
from the first node of the primary root at the two- or three-leaf stage. The next node gives rise to the
second pair of secondary roots, and thereafter, four to six roots are produced at each node. These roots
can penetrate up to a depth of 5 m into the soil.
C r o w n or b r a c e r o o t s . These roots develop from the lower nodes of the stem at or above ground level.
They provide anchorage to the plant.
plant.
The maximum root spread in pearl millet is confined to 25-30 cm
of the soil area around the
Shoot System
The pearl millet shoot consists of a stem, tillers, and leaves during the vegetative stage (Fig. 3).
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