Seed Production in Hybrid Jowar and Bajara
Special techniques related to commercial seed production of hybrids.
1) Cytoplasmic Genetic Male Sterility:
Male sterility due to interaction between cytoplasmic factors and nuclear factors is termed as cytoplasmic genetic male sterility. Now days, this is used in Jowar, Bajara, Maize, Cotton and Rice crops.
2) Male Sterile Line (A line):
It is the female parent of the hybrid which does not produce functional (fertile) pollens. It is designated as A line or M.S. line, E .g 2077A, 296A,CK-60A, AKMS14A, 27A.
3) Male Fertile Line (B line):
It is the isogenic line of male sterile line with only one difference that it produces functional (Fertilized) pollens. It is designated as a b line or maintainer line E. g 2077B, 296 B, CK-60B.
4) Restorer line (R line):
It is the male parent of hybrid and when it is crossed with male sterile line it restore fertility in the resulting hybrid. It is designated as R line E.g IS84, CS-3541, AKR150, RS-29, RS-585, C43.
5) Pollen Shedders:
These are the plants of B line present in the A line in hybrid seed production.
It is simultaneous flowering of male and female parents in seed production is known as synchronization. It is essential for commercial large scale production of hybrids in different crops.
The synchrony in flowering of male and female parent is termed as nicking.
8) Planting Ratio:
It refers to the optimum number of female parent rows to the number of row in male parent in hybrid seed production plot for cent percent seed setting in female / seed parent in crossing block. It depends upon nature of pollination, pollen viability, and stigma respectively, wind velocity, height of male parent in crossing block.
9) Border Rows:
In hybrid seed production plot, minimum male parent rows, are grown ground the seed plot in order to supply continuous ample pollens to seed parent and also to avoid natural cross pollination and mechanical mixture etc these rows are termed on border rows.
Stages of Seed Production in Sorghum and Bajara Hybrids:
A line, B line, A X B programme for of ‘A1’
A line, B line, R line B X B Programme for multiplication of B line and R X R programme for multiplication of R line.
A X R lines (hybrids) A X R programme for multiplication.
Notified Jowar hybrids and their parents of Hybrid ( F1) which is harvested from A line,
Female Parent ( A line)
Male Parent ( R line)
M 148 -138
Female Parent ( A line)
Male Parent ( R line)
RHRB 1 A
Selection of Land:
The land selected for seed production of Jowar/ Bajara hybrids should have medium to deep and well drained soils. The land should be more or less uniformity leveled. The land selected for hybrid/Bajara/Jawar seed production should not have preveious crop of Jawar / Bajara. In case, Jowar/ Bajara. In case, Jowar, Bajara crop is taken during preveious season or year, the land should be irrigated at least 3 weeks before sowing of seed plot and germination Jowar/Bajara seeds should be removed by harrowing.
Isolation distance prescribed for foundation and certified by Jawar, hybrid Bajara seed production is as detailed below:
Isolation Distance for Jawar (m)
Isolation Distance for Bajara (m)
1. Fields of other varieties and hybrids
2. Fields of same varieties or hybrids not confirming the varietal purity requirement.
3. From forage sorghum
4. From grassy sorghums and Johnson grass ( Sorghum halepense)
No Jowar plants or Johnson grass plants be allowed to grow within isolation distance on all sides of the seed plot.
As Jawar crop is well adopted to Kharif, Rabi and Summer season, the hybrid seed production can be taken during any season. However on the basis of past experience , the hybrid seed production should be taken during Kharif season and it should be avoided during rabi and summer seasons because-
1. Climate condition viz. Temperature, relative humidity, in Kharif season are congenial for pollination and good seed setting.
2. Some of the parents of Jawar hybrid are thermosesitive i.e R lines like CS-3541 fail to dehisce pollens during winter at low temperature. During summer seasons, pollens desiccate rapidly at high temperature and loose their viability. Similarly receptivity of stigma in some female parents is badly affected due to low temperatures. This causes very poor seed setting.
3. Growth of either male or female parent of hybrids is slower as compared to other parent as a result of which there is a problem of nicking which thereby results in poor seed setting.