Prakash D. Chavan

Growth, mineral nutrition, organic constituents and rate of photosynthesis inSesbania grandiflora L. grown under saline conditions

SummarySesbania showed a luxuriant growth in soil with an electrical conductivity of up to 10 m Scm−1. Under saline conditions Na and Cl accumulated at different rates in the plants. Accumulation of these ions in the leaf rachis compared with leaflets appears to be an adaptive feature of this legume. Maintenance of an optimum K level and accumulation of Ca are also indicative of a salt-tolerance mechanism. Accumulation of Fe in the roots of salt-stressed plants is noteworthy. Organic acids and soluble sugars which accumulated in plants under stress condition may play a role in osmotic adjustment. The level of proline, however, remained unaltered. Though the chlorophyll content of the leaves decreased, the photosynthetic rate was found to be enhanced by saline conditions. The probable relationships between these changes and the salt tolerance mechanism in the plant have been discussed.

Influence of salinity on mineral nutrition of peanut (Arachis hypogea L.)

SummaryEffect of sodium chloride and sodium sulphate salinities on growth and mineral nutrition of peanut (A. hypogea L.) variety TMV-10 has been studied. Both salts suppressed growth of the plants. The inorganic analysis revealed that NaCl and Na2SO4 caused accumulation of Na, P, Fe and Mn in root, stem, leaf and gynophore. NaCl treatment caused accumulation of Cl in these parts. The uptake of K was hampered by both salts whereas Ca uptake was retarded mainly by Na2SO4. The results are discussed in relation to the salt tolerance capacity of the plant.

Influence of sodium chloride and sodium sulfate salinities on photosynthetic carbon assimilation in peanut.

SummaryThe effect of NaCl and Na2SO4 treatments on chlorophyll content, rate of14C assimilation and products of photosynthesis in peanut (Arachis hypogaea L.) variety TMV-10 has been investigated. It was observed that chlorophyll content was affected mainly by NaCl. Na2SO4 treatment lowered the rate of photosynthetic14CO2 fixation. The analysis of labelled products revealed that the salts affect the carbon metabolism differently. The radioactivity was found to be accumulated in fractions of sugars and sugarphosphates in the leaves of NaCl treated plants. Na2SO4 treatment brought about considerable decline in labelling of sugars and an increase in labelling of amino acids and sugarphosphates.

Influence of salt stress on biochemical processes in chickpea,Cicer arietinum L.

SummarySome biochemical processes in pods of chickpea (Cicer arietinum L.) plants subjected to increasing levels of NaCl salinity in sand culture have been investigated. Chickpea exhibited a marked salt sensitivity with respect to yield characteristics such as number of pods per plant, number of filled pods and 100 pod and seed weight. The accumulation of Na and Cl was more pronounced in the pod shell as compared to that in seeds. The Ca content in pod shell showed a decrease under saline conditions whereas an opposite trend was exhibited by P. Under saline conditions the levels of Fe, Mn and Mg were lowered in the seed tissue. The protein and starch contents of the seeds were also reduced markedly under saline conditions while only minor changes in the sugar fraction were found. Salinity favoured accumulation of free proline in the pod shell as well as in the seeds. Salt stress caused reduction of photosynthetic carbon assimilation in pods with a change in pattern of carbon metabolism.

Physiological studies in salinity tolerance ofSesbania aculeata POIR

A pot culture experiment was performed to evaluate salt tolerance potential ofSesbania aculeataPoir. The plant can tolerate salinity levels up to electrical conductivity (ECe), 10 mS cm−1 and at 15 mS cm−1 thero is about 40% reduction in dry matter production. The analysis of inorganic constituents in different plant parts revealed that the plant has the capacity to regulate sodium uptake under saline conditions and chloride uptake always exceeded that of sodium. The potassium: sodium ratio is also maintained at a fairly constant level in leaflets while it is reduced in leaf rachis, stem and roots. Salt stress caused accumulation of calcium and magnesium in all plant parts. A considerable decline in phosphorus uptake was observed due to salinity. Iron was found to be accumulated more in salt stressed roots only. Nitrogen accumulated in both roots and leaves while considerable proline accumulation was observed in leaves of salt stressed plants. The amount of soluble sugars was increased in roots and leaves due to salt stress, while starch content of roots decreased. Those changes induced by salinity are discussed in relation to salt tolerance capacity of the plant.

Effect of salinity on translocation of assimilates in french bean

The effect of sodium chloride and sodium sulphate salinities on the rate of translocation of photosynthates in french bean at the pod filling stage was investigated. Both salt treatments exerted a negative influence on the translocation of photosynthetic assimilates and in this respect the NaCl treatment was more detrimental than that of Na2SO4. The transport of radioactivity from the source to the sink (pod) and other plant parts such as leaves, stem and roots was adversely affected by both salinity regimes.