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A reliable estimate of tolerance to salinity of the
genotypes is reflected from the data of Table
2. The yield ranged from 287.5 (Bhp 31) to 389.3 g (Bhp
36) against 339.8 g for control. The former thus yielded
significantly higher whereas latter lower to control
variety. The mutant Bhp 36 also showed maximum values on
Mean Salinity Index (MSI), least reduction at abrupt
salinity over control and regression slope, encouragingly
50% yield decline was also associated with the highest (14
mmhos/cm) salinity. This mutant may, therefore be considered
better tolerant to HD 2009. Similarly, the mutant Bhp 31 was
rather sensitive and Bhp 30 was a medium tolerant. Results
of KUMAR et al. (1981) are similar that tolerance was
associated to higher MSI values and lower regression
slope.
Mineral accumulation in leaf and grain may reflect adjusting
tendency of plants to saline environment. The accumulation
of K, Ca and Na was more in leaf whereas N and P were more
accumulated in grain. Thus, translocation of former three
was inhibited from leaf to grain whereas latter two were
translocated to grain. Furthermore, the concentration of N
and Na increased whereas that of P and K decreased with
rising salinity. No trend was, however, observed for Ca. The
tolerant mutant Bhp 36 was characterized by maximum
accumulation of K in leaf and grain in conj unction with
least concentration of Na in leaf. This phenomenon has been
referred to as selectivity of ion transport by LEVITT
(1972). Bhp 36 has, therefore, tolerated salinity by
adjusting due to accumulation of more K and restricting
deleterious ion Na. Potassium has been found a chief osmotic
gradiant in a wide range of crops and its more accumulation
helps in causing fast penetration into cell sap and
increasing water retention capacity of cell protoplasm.
Table 3. Effect of saline water
on certain minerals* in leaf (flowering stage) and grain
(maturity) in control and induced mutants
References
CHAUHAN, R.P.S., C,P.S. CHAUHAN and D. KUMAR 1980. Free
proline accumulation in cereals in relation to salt
tolerance. Plant Soil. 57: 167-175.
KUMAR, D. 1978. The impact of seed moisture on
radiosensitivity, mutation frequency and spectrum following
gamma ray treatment of wheat cultivars HD 1553 and HD 2009.
Indian J. Hered. 10(3): 19-28.
KUMAR, D., R.P.S. CHAUHAN and R.V. SINGH 1980. Performance
of certain mutants of common wheat for yield and nutritional
quality under salinity. Wheat Inform. Serv. 51:
26-28.
KUMAR, D., R.P.S. CHAUHAN and R.V. SINGH 1981. Salt
tolerance of some induced mutants of HD- 2009. Indian J.
Agric. Sci. 5(7): 475-479.
Levitt, J. 1972. Salt and ion stress. In Response of
plants to environmental stresses. Acad. Press, NY pp
489-530.
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