The morphological characteristics and proximate components of 23 accessions of prickly pear (Opun... more The morphological characteristics and proximate components of 23 accessions of prickly pear (Opuntia Spp.) were investigated. Variation was seen in the cladode's length, width, thickness, and weight, as well as the height and spread of plants. Cladodes were good water reservoirs and had an acidic pH. They were composed of mucilage, which possesses a great capacity for retaining water and oil. They were rich in crude fibre and total carbohydrates while low in true protein and crude fat. They were also abundant in macro-minerals, viz. calcium and potassium, and in micro-minerals like ferrous and manganese, followed by zinc and copper. There was a wide variability of various parameters amongst the Opuntia accessions. The high water content and the presence of health-promoting agents such as crude fibre, macro and micro minerals ensure the utility of this plant as a fodder and vegetable in the arid and semi-arid regions of India.
The oyster mushroom (Pleurotus ostreatus) was cultivated on diverse substrates,
encompassing whea... more The oyster mushroom (Pleurotus ostreatus) was cultivated on diverse substrates, encompassing wheat straw (T1), paddy straw (T2), groundnut leaves and straw (T3), sugarcane bagasses (T4), cotton stalk (T5), coconut husk (T6), pigeon pea straw (T7), and banana pseudostem (T8). The study comprised of the estimation of proximate composition, antioxidants, and mineral content of the sun-dried mushrooms during the initial two harvests. The average values of nutritional parameters were as follows: moisture (90.93 to 85.18 %), ash (7.62 to 4.86%), carbohydrates (37.57 to 20.10%), crude protein (45.45 to 23.10%), crude fiber (29.08 to 19.29%), crude fat (2.68 to 1.63%), total phenol (14.23 to 9.12 mg/g) and ascorbic acid (11.58 to 8.72 mg/100g). The average mineral content exhibited the trend K>P>Mg>Ca>Zn>Fe>Cu. Upon consideration of average values from both harvests, the groundnut leaves and straw had the highest crude protein (45.45 %), total phenol (14.23 mg/g), ascorbic acid (11.58 mg/100g), phosphorous (0.43 %), iron (7.12 mg/100g) and zinc (12.43 mg/100g). The paddy straw resulted in the highest crude fiber (29.08 %) and crude fat (2.68 %), while the wheat straw resulted in the highest potassium (1.52 %) and calcium (179.65 mg/100g). The various substrates had an impact on nutritional parameters as seen by either an increase or decrease in various parameters which can be reflected in turn by the composition of the substrates itself. In conclusion, groundnut leaves and straw (T3) along with paddy straw (T2) and wheat straw (T1) resulted in significant improvement of nutritional composition compared to other treatments. This study underscores the environmentally friendly utilization of nutrients from agricultural waste for mushroom production.
A pot experiment was conducted to evaluate the effect of foliar application of silicon (Si) at di... more A pot experiment was conducted to evaluate the effect of foliar application of silicon (Si) at different stages of growth in wheat. Foliar treatment of silicon was given on 15th and 30th days after germination (DAG) and the plants were subjected to water deficit stress at booting, flowering and grain filling stages. The greater decline for relative water content (RWC) and hydrogen peroxide (H2O2) was observed in drought (Dr) as compared to Si + Dr treatment. Si + Dr treatment resulted in the lowest rise in malondialdehyde (MDA) from booting to grain filling stage. With the progression of plant age the peroxidase (POX), ascorbate peroxidase (APX) and catalase (CAT) enzyme activity declined. The water deficit stress induced greater increase in POX and APX activity in tolerant variety. Si + Dr treatment was able to counter the decline caused in CAT activity due to the implication of water deficit stress. Overall, the silicon treatment reduced the oxidative stress.
Silicon's role in mediating resistance against various stresses has been a matter of focus in the... more Silicon's role in mediating resistance against various stresses has been a matter of focus in the past decade. Poaeceae family plants are known as high accumulators of silicon. Wheat shows rapid absorption, the optimum accumulation of silicon occurring at around 20 days. Silicon plays a role as a mechanical and a physiological barrier. It also alters the levels of osmolytes and antioxidant enzymes which are a first line of defense in the water deficit stress; also reducing the levels of oxidative stress factors such as hydrogen peroxide. But the results vary with respect to the modes of stress application and its duration. Nowadays, foliar mode of silicon application is carried out compared to the traditional soil application yielding some promising results. Further studies are needed to confirm the mechanisms governing protection which can be done with the comparison of the transcriptome analysis of the stressed plants and also microscopic studies revealing the site of deposition.
Protein and DNA profiling of five resistant and two susceptible pearl millet genotypes to downy
... more Protein and DNA profiling of five resistant and two susceptible pearl millet genotypes to downy
mildew were investigated. Characterization of total seed proteins using SDS-PAGE was performed.
The resistant genotypes had more number of bands (9-14) whereas; susceptible genotypes had fewer
bands (4-6). Two bands having Rm values 0.27 and 0.36 were specifically present in all the five
resistant genotypes, and were absent in both the susceptible genotypes. The PCR amplification was
performed using 120 oligonucleotide decamer primers of arbitrary sequence; however only 14
oligonulcleotide primers yielding more than six PCR fragments were selected. Five PCR fragments
obtained in resistant genotypes with OPB 18, OPE 12, OPI 1, OPI 14 and OPK 10 reactions respectively
showed its possible linkage with downy mildew resistance gene. The result of protein and DNA
profiling suggests suitability of this technique for screening of different pearl millet genotypes against
S. graminicola. The development of SCAR can aid in rapid and reliable screening.
Indian Journal of Agricultural Biochemistry, Jun 30, 2014
In the present study, five resistant and two susceptible pearl millet genotypes against downy mil... more In the present study, five resistant and two susceptible pearl millet genotypes against downy mildew were analyzed for
antioxidant and defense related enzymes and isozymes at seedling stage. Proximate analysis was performed with the
seeds. Peroxidase and ascorbate peroxidase activities were higher in resistant genotypes at both two and five days after
germination (DAG) stage, whereas catalase activity was higher amongst the resistant genotypes at five DAG stage. Both
peroxidase and polyphenol oxidase isozymes were able to discriminate amongst these genotypes at five DAG stages
differentially as well as qualitatively. Proximate analysis in general failed to give a clear indication to distinguish these
genotypes based on their nature against the downy mildew disease. Therefore, antioxidant enzyme activity and isozymes
may prove useful to differentiate the genotypes for resistance and susceptibility against downy mildew disease.
The present investigation was carried out for screening of pearl millet entries with respect to d... more The present investigation was carried out for screening of pearl millet entries with respect to downy mildew disease. Study of isozymes (peroxidase, esterase and polyphenol oxidase) and stress proteins was carried out at 30 and 50 days growth stages. Amongst the two stages, 50 days stage was found more appropriate for screening of entries of pearl millet against downy mildew. Quantitative difference in banding of peroxidase was observed at this stage amongst the resistant and susceptible entries. There was presence of unique isoforms with Rm values 0.29, 0.58 and 0.15 with dark, medium and varying intensity, respectively in most of the resistant entries. Esterase banding pattern revealed both quantitative as well as qualitative differences amongst the entries. Moderate to high intensity isoforms were found in resistant entries whereas susceptible entries showed more number of isoforms. Two unique isoforms were present in most of the resistant entries, one (Rm 0.39) with dark intensity at 50 days growth stage and other (Rm 0.75) having varying intensity at 30 days growth stage. Polyphenol oxidase failed to distinguish amongst the resistant and susceptible entries. Leaf protein banding pattern at both stages can be useful provided low intensity bands are considered. The specific differentiation in peroxidase and esterase isozyme pattern can be useful for screening of genotypes against downy mildew resistance.
Eighteen pearl millet (Pennisetum glaucum L.) entries
were screened to find out biochemical trai... more Eighteen pearl millet (Pennisetum glaucum L.) entries
were screened to find out biochemical traits in relation to
downy mildew. Peroxidase activity was determined after 30
and 50 days, whereas phenol, silicon content were estimated
at 30 days stage. Results showed that, at 30 days the peroxidase
activity was lower in resistant entries and higher in susceptible
entries, whereas this trend was reversed at 50 days. Negative
correlation was obtained at 50 days between disease incidence
and peroxidase activity. Phenol content showed positive
correlation with disease incidence but the difference was
non-significant amongst resistant and susceptible entries.
There was a positive relationship between silicon level in
various entries and their degree of disease resistance. In
resistant entry lignin deposition was more in vessel walls,
cortical parenchyma cells and cuticle layer, while it was very
less in susceptible entry at 50 days. Thus, peroxidase activity
and silicon content can be useful traits in relation to downy
mildew in pearl millet.
The morphological characteristics and proximate components of 23 accessions of prickly pear (Opun... more The morphological characteristics and proximate components of 23 accessions of prickly pear (Opuntia Spp.) were investigated. Variation was seen in the cladode's length, width, thickness, and weight, as well as the height and spread of plants. Cladodes were good water reservoirs and had an acidic pH. They were composed of mucilage, which possesses a great capacity for retaining water and oil. They were rich in crude fibre and total carbohydrates while low in true protein and crude fat. They were also abundant in macro-minerals, viz. calcium and potassium, and in micro-minerals like ferrous and manganese, followed by zinc and copper. There was a wide variability of various parameters amongst the Opuntia accessions. The high water content and the presence of health-promoting agents such as crude fibre, macro and micro minerals ensure the utility of this plant as a fodder and vegetable in the arid and semi-arid regions of India.
The oyster mushroom (Pleurotus ostreatus) was cultivated on diverse substrates,
encompassing whea... more The oyster mushroom (Pleurotus ostreatus) was cultivated on diverse substrates, encompassing wheat straw (T1), paddy straw (T2), groundnut leaves and straw (T3), sugarcane bagasses (T4), cotton stalk (T5), coconut husk (T6), pigeon pea straw (T7), and banana pseudostem (T8). The study comprised of the estimation of proximate composition, antioxidants, and mineral content of the sun-dried mushrooms during the initial two harvests. The average values of nutritional parameters were as follows: moisture (90.93 to 85.18 %), ash (7.62 to 4.86%), carbohydrates (37.57 to 20.10%), crude protein (45.45 to 23.10%), crude fiber (29.08 to 19.29%), crude fat (2.68 to 1.63%), total phenol (14.23 to 9.12 mg/g) and ascorbic acid (11.58 to 8.72 mg/100g). The average mineral content exhibited the trend K>P>Mg>Ca>Zn>Fe>Cu. Upon consideration of average values from both harvests, the groundnut leaves and straw had the highest crude protein (45.45 %), total phenol (14.23 mg/g), ascorbic acid (11.58 mg/100g), phosphorous (0.43 %), iron (7.12 mg/100g) and zinc (12.43 mg/100g). The paddy straw resulted in the highest crude fiber (29.08 %) and crude fat (2.68 %), while the wheat straw resulted in the highest potassium (1.52 %) and calcium (179.65 mg/100g). The various substrates had an impact on nutritional parameters as seen by either an increase or decrease in various parameters which can be reflected in turn by the composition of the substrates itself. In conclusion, groundnut leaves and straw (T3) along with paddy straw (T2) and wheat straw (T1) resulted in significant improvement of nutritional composition compared to other treatments. This study underscores the environmentally friendly utilization of nutrients from agricultural waste for mushroom production.
A pot experiment was conducted to evaluate the effect of foliar application of silicon (Si) at di... more A pot experiment was conducted to evaluate the effect of foliar application of silicon (Si) at different stages of growth in wheat. Foliar treatment of silicon was given on 15th and 30th days after germination (DAG) and the plants were subjected to water deficit stress at booting, flowering and grain filling stages. The greater decline for relative water content (RWC) and hydrogen peroxide (H2O2) was observed in drought (Dr) as compared to Si + Dr treatment. Si + Dr treatment resulted in the lowest rise in malondialdehyde (MDA) from booting to grain filling stage. With the progression of plant age the peroxidase (POX), ascorbate peroxidase (APX) and catalase (CAT) enzyme activity declined. The water deficit stress induced greater increase in POX and APX activity in tolerant variety. Si + Dr treatment was able to counter the decline caused in CAT activity due to the implication of water deficit stress. Overall, the silicon treatment reduced the oxidative stress.
Silicon's role in mediating resistance against various stresses has been a matter of focus in the... more Silicon's role in mediating resistance against various stresses has been a matter of focus in the past decade. Poaeceae family plants are known as high accumulators of silicon. Wheat shows rapid absorption, the optimum accumulation of silicon occurring at around 20 days. Silicon plays a role as a mechanical and a physiological barrier. It also alters the levels of osmolytes and antioxidant enzymes which are a first line of defense in the water deficit stress; also reducing the levels of oxidative stress factors such as hydrogen peroxide. But the results vary with respect to the modes of stress application and its duration. Nowadays, foliar mode of silicon application is carried out compared to the traditional soil application yielding some promising results. Further studies are needed to confirm the mechanisms governing protection which can be done with the comparison of the transcriptome analysis of the stressed plants and also microscopic studies revealing the site of deposition.
Protein and DNA profiling of five resistant and two susceptible pearl millet genotypes to downy
... more Protein and DNA profiling of five resistant and two susceptible pearl millet genotypes to downy
mildew were investigated. Characterization of total seed proteins using SDS-PAGE was performed.
The resistant genotypes had more number of bands (9-14) whereas; susceptible genotypes had fewer
bands (4-6). Two bands having Rm values 0.27 and 0.36 were specifically present in all the five
resistant genotypes, and were absent in both the susceptible genotypes. The PCR amplification was
performed using 120 oligonucleotide decamer primers of arbitrary sequence; however only 14
oligonulcleotide primers yielding more than six PCR fragments were selected. Five PCR fragments
obtained in resistant genotypes with OPB 18, OPE 12, OPI 1, OPI 14 and OPK 10 reactions respectively
showed its possible linkage with downy mildew resistance gene. The result of protein and DNA
profiling suggests suitability of this technique for screening of different pearl millet genotypes against
S. graminicola. The development of SCAR can aid in rapid and reliable screening.
Indian Journal of Agricultural Biochemistry, Jun 30, 2014
In the present study, five resistant and two susceptible pearl millet genotypes against downy mil... more In the present study, five resistant and two susceptible pearl millet genotypes against downy mildew were analyzed for
antioxidant and defense related enzymes and isozymes at seedling stage. Proximate analysis was performed with the
seeds. Peroxidase and ascorbate peroxidase activities were higher in resistant genotypes at both two and five days after
germination (DAG) stage, whereas catalase activity was higher amongst the resistant genotypes at five DAG stage. Both
peroxidase and polyphenol oxidase isozymes were able to discriminate amongst these genotypes at five DAG stages
differentially as well as qualitatively. Proximate analysis in general failed to give a clear indication to distinguish these
genotypes based on their nature against the downy mildew disease. Therefore, antioxidant enzyme activity and isozymes
may prove useful to differentiate the genotypes for resistance and susceptibility against downy mildew disease.
The present investigation was carried out for screening of pearl millet entries with respect to d... more The present investigation was carried out for screening of pearl millet entries with respect to downy mildew disease. Study of isozymes (peroxidase, esterase and polyphenol oxidase) and stress proteins was carried out at 30 and 50 days growth stages. Amongst the two stages, 50 days stage was found more appropriate for screening of entries of pearl millet against downy mildew. Quantitative difference in banding of peroxidase was observed at this stage amongst the resistant and susceptible entries. There was presence of unique isoforms with Rm values 0.29, 0.58 and 0.15 with dark, medium and varying intensity, respectively in most of the resistant entries. Esterase banding pattern revealed both quantitative as well as qualitative differences amongst the entries. Moderate to high intensity isoforms were found in resistant entries whereas susceptible entries showed more number of isoforms. Two unique isoforms were present in most of the resistant entries, one (Rm 0.39) with dark intensity at 50 days growth stage and other (Rm 0.75) having varying intensity at 30 days growth stage. Polyphenol oxidase failed to distinguish amongst the resistant and susceptible entries. Leaf protein banding pattern at both stages can be useful provided low intensity bands are considered. The specific differentiation in peroxidase and esterase isozyme pattern can be useful for screening of genotypes against downy mildew resistance.
Eighteen pearl millet (Pennisetum glaucum L.) entries
were screened to find out biochemical trai... more Eighteen pearl millet (Pennisetum glaucum L.) entries
were screened to find out biochemical traits in relation to
downy mildew. Peroxidase activity was determined after 30
and 50 days, whereas phenol, silicon content were estimated
at 30 days stage. Results showed that, at 30 days the peroxidase
activity was lower in resistant entries and higher in susceptible
entries, whereas this trend was reversed at 50 days. Negative
correlation was obtained at 50 days between disease incidence
and peroxidase activity. Phenol content showed positive
correlation with disease incidence but the difference was
non-significant amongst resistant and susceptible entries.
There was a positive relationship between silicon level in
various entries and their degree of disease resistance. In
resistant entry lignin deposition was more in vessel walls,
cortical parenchyma cells and cuticle layer, while it was very
less in susceptible entry at 50 days. Thus, peroxidase activity
and silicon content can be useful traits in relation to downy
mildew in pearl millet.
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Papers by Sarang Sapre
encompassing wheat straw (T1), paddy straw (T2), groundnut leaves and straw
(T3), sugarcane bagasses (T4), cotton stalk (T5), coconut husk (T6), pigeon pea
straw (T7), and banana pseudostem (T8). The study comprised of the estimation
of proximate composition, antioxidants, and mineral content of the sun-dried
mushrooms during the initial two harvests. The average values of nutritional
parameters were as follows: moisture (90.93 to 85.18 %), ash (7.62 to 4.86%),
carbohydrates (37.57 to 20.10%), crude protein (45.45 to 23.10%), crude fiber
(29.08 to 19.29%), crude fat (2.68 to 1.63%), total phenol (14.23 to 9.12 mg/g)
and ascorbic acid (11.58 to 8.72 mg/100g). The average mineral content
exhibited the trend K>P>Mg>Ca>Zn>Fe>Cu. Upon consideration of average
values from both harvests, the groundnut leaves and straw had the highest crude
protein (45.45 %), total phenol (14.23 mg/g), ascorbic acid (11.58 mg/100g),
phosphorous (0.43 %), iron (7.12 mg/100g) and zinc (12.43 mg/100g). The paddy
straw resulted in the highest crude fiber (29.08 %) and crude fat (2.68 %), while
the wheat straw resulted in the highest potassium (1.52 %) and calcium (179.65
mg/100g). The various substrates had an impact on nutritional parameters as
seen by either an increase or decrease in various parameters which can be
reflected in turn by the composition of the substrates itself. In conclusion,
groundnut leaves and straw (T3) along with paddy straw (T2) and wheat straw
(T1) resulted in significant improvement of nutritional composition compared to
other treatments. This study underscores the environmentally friendly
utilization of nutrients from agricultural waste for mushroom production.
wheat. Foliar treatment of silicon was given on 15th and 30th days after germination (DAG) and the plants were subjected to
water deficit stress at booting, flowering and grain filling stages. The greater decline for relative water content (RWC) and
hydrogen peroxide (H2O2) was observed in drought (Dr) as compared to Si + Dr treatment. Si + Dr treatment resulted in the
lowest rise in malondialdehyde (MDA) from booting to grain filling stage. With the progression of plant age the peroxidase
(POX), ascorbate peroxidase (APX) and catalase (CAT) enzyme activity declined. The water deficit stress induced greater
increase in POX and APX activity in tolerant variety. Si + Dr treatment was able to counter the decline caused in CAT activity
due to the implication of water deficit stress. Overall, the silicon treatment reduced the oxidative stress.
mildew were investigated. Characterization of total seed proteins using SDS-PAGE was performed.
The resistant genotypes had more number of bands (9-14) whereas; susceptible genotypes had fewer
bands (4-6). Two bands having Rm values 0.27 and 0.36 were specifically present in all the five
resistant genotypes, and were absent in both the susceptible genotypes. The PCR amplification was
performed using 120 oligonucleotide decamer primers of arbitrary sequence; however only 14
oligonulcleotide primers yielding more than six PCR fragments were selected. Five PCR fragments
obtained in resistant genotypes with OPB 18, OPE 12, OPI 1, OPI 14 and OPK 10 reactions respectively
showed its possible linkage with downy mildew resistance gene. The result of protein and DNA
profiling suggests suitability of this technique for screening of different pearl millet genotypes against
S. graminicola. The development of SCAR can aid in rapid and reliable screening.
antioxidant and defense related enzymes and isozymes at seedling stage. Proximate analysis was performed with the
seeds. Peroxidase and ascorbate peroxidase activities were higher in resistant genotypes at both two and five days after
germination (DAG) stage, whereas catalase activity was higher amongst the resistant genotypes at five DAG stage. Both
peroxidase and polyphenol oxidase isozymes were able to discriminate amongst these genotypes at five DAG stages
differentially as well as qualitatively. Proximate analysis in general failed to give a clear indication to distinguish these
genotypes based on their nature against the downy mildew disease. Therefore, antioxidant enzyme activity and isozymes
may prove useful to differentiate the genotypes for resistance and susceptibility against downy mildew disease.
Study of isozymes (peroxidase, esterase and polyphenol oxidase) and stress proteins was carried out at 30 and 50 days
growth stages. Amongst the two stages, 50 days stage was found more appropriate for screening of entries of pearl
millet against downy mildew. Quantitative difference in banding of peroxidase was observed at this stage amongst the
resistant and susceptible entries. There was presence of unique isoforms with Rm values 0.29, 0.58 and 0.15 with dark,
medium and varying intensity, respectively in most of the resistant entries. Esterase banding pattern revealed both
quantitative as well as qualitative differences amongst the entries. Moderate to high intensity isoforms were found in
resistant entries whereas susceptible entries showed more number of isoforms. Two unique isoforms were present in
most of the resistant entries, one (Rm 0.39) with dark intensity at 50 days growth stage and other (Rm 0.75) having varying
intensity at 30 days growth stage. Polyphenol oxidase failed to distinguish amongst the resistant and susceptible entries.
Leaf protein banding pattern at both stages can be useful provided low intensity bands are considered. The specific
differentiation in peroxidase and esterase isozyme pattern can be useful for screening of genotypes against downy
mildew resistance.
were screened to find out biochemical traits in relation to
downy mildew. Peroxidase activity was determined after 30
and 50 days, whereas phenol, silicon content were estimated
at 30 days stage. Results showed that, at 30 days the peroxidase
activity was lower in resistant entries and higher in susceptible
entries, whereas this trend was reversed at 50 days. Negative
correlation was obtained at 50 days between disease incidence
and peroxidase activity. Phenol content showed positive
correlation with disease incidence but the difference was
non-significant amongst resistant and susceptible entries.
There was a positive relationship between silicon level in
various entries and their degree of disease resistance. In
resistant entry lignin deposition was more in vessel walls,
cortical parenchyma cells and cuticle layer, while it was very
less in susceptible entry at 50 days. Thus, peroxidase activity
and silicon content can be useful traits in relation to downy
mildew in pearl millet.
encompassing wheat straw (T1), paddy straw (T2), groundnut leaves and straw
(T3), sugarcane bagasses (T4), cotton stalk (T5), coconut husk (T6), pigeon pea
straw (T7), and banana pseudostem (T8). The study comprised of the estimation
of proximate composition, antioxidants, and mineral content of the sun-dried
mushrooms during the initial two harvests. The average values of nutritional
parameters were as follows: moisture (90.93 to 85.18 %), ash (7.62 to 4.86%),
carbohydrates (37.57 to 20.10%), crude protein (45.45 to 23.10%), crude fiber
(29.08 to 19.29%), crude fat (2.68 to 1.63%), total phenol (14.23 to 9.12 mg/g)
and ascorbic acid (11.58 to 8.72 mg/100g). The average mineral content
exhibited the trend K>P>Mg>Ca>Zn>Fe>Cu. Upon consideration of average
values from both harvests, the groundnut leaves and straw had the highest crude
protein (45.45 %), total phenol (14.23 mg/g), ascorbic acid (11.58 mg/100g),
phosphorous (0.43 %), iron (7.12 mg/100g) and zinc (12.43 mg/100g). The paddy
straw resulted in the highest crude fiber (29.08 %) and crude fat (2.68 %), while
the wheat straw resulted in the highest potassium (1.52 %) and calcium (179.65
mg/100g). The various substrates had an impact on nutritional parameters as
seen by either an increase or decrease in various parameters which can be
reflected in turn by the composition of the substrates itself. In conclusion,
groundnut leaves and straw (T3) along with paddy straw (T2) and wheat straw
(T1) resulted in significant improvement of nutritional composition compared to
other treatments. This study underscores the environmentally friendly
utilization of nutrients from agricultural waste for mushroom production.
wheat. Foliar treatment of silicon was given on 15th and 30th days after germination (DAG) and the plants were subjected to
water deficit stress at booting, flowering and grain filling stages. The greater decline for relative water content (RWC) and
hydrogen peroxide (H2O2) was observed in drought (Dr) as compared to Si + Dr treatment. Si + Dr treatment resulted in the
lowest rise in malondialdehyde (MDA) from booting to grain filling stage. With the progression of plant age the peroxidase
(POX), ascorbate peroxidase (APX) and catalase (CAT) enzyme activity declined. The water deficit stress induced greater
increase in POX and APX activity in tolerant variety. Si + Dr treatment was able to counter the decline caused in CAT activity
due to the implication of water deficit stress. Overall, the silicon treatment reduced the oxidative stress.
mildew were investigated. Characterization of total seed proteins using SDS-PAGE was performed.
The resistant genotypes had more number of bands (9-14) whereas; susceptible genotypes had fewer
bands (4-6). Two bands having Rm values 0.27 and 0.36 were specifically present in all the five
resistant genotypes, and were absent in both the susceptible genotypes. The PCR amplification was
performed using 120 oligonucleotide decamer primers of arbitrary sequence; however only 14
oligonulcleotide primers yielding more than six PCR fragments were selected. Five PCR fragments
obtained in resistant genotypes with OPB 18, OPE 12, OPI 1, OPI 14 and OPK 10 reactions respectively
showed its possible linkage with downy mildew resistance gene. The result of protein and DNA
profiling suggests suitability of this technique for screening of different pearl millet genotypes against
S. graminicola. The development of SCAR can aid in rapid and reliable screening.
antioxidant and defense related enzymes and isozymes at seedling stage. Proximate analysis was performed with the
seeds. Peroxidase and ascorbate peroxidase activities were higher in resistant genotypes at both two and five days after
germination (DAG) stage, whereas catalase activity was higher amongst the resistant genotypes at five DAG stage. Both
peroxidase and polyphenol oxidase isozymes were able to discriminate amongst these genotypes at five DAG stages
differentially as well as qualitatively. Proximate analysis in general failed to give a clear indication to distinguish these
genotypes based on their nature against the downy mildew disease. Therefore, antioxidant enzyme activity and isozymes
may prove useful to differentiate the genotypes for resistance and susceptibility against downy mildew disease.
Study of isozymes (peroxidase, esterase and polyphenol oxidase) and stress proteins was carried out at 30 and 50 days
growth stages. Amongst the two stages, 50 days stage was found more appropriate for screening of entries of pearl
millet against downy mildew. Quantitative difference in banding of peroxidase was observed at this stage amongst the
resistant and susceptible entries. There was presence of unique isoforms with Rm values 0.29, 0.58 and 0.15 with dark,
medium and varying intensity, respectively in most of the resistant entries. Esterase banding pattern revealed both
quantitative as well as qualitative differences amongst the entries. Moderate to high intensity isoforms were found in
resistant entries whereas susceptible entries showed more number of isoforms. Two unique isoforms were present in
most of the resistant entries, one (Rm 0.39) with dark intensity at 50 days growth stage and other (Rm 0.75) having varying
intensity at 30 days growth stage. Polyphenol oxidase failed to distinguish amongst the resistant and susceptible entries.
Leaf protein banding pattern at both stages can be useful provided low intensity bands are considered. The specific
differentiation in peroxidase and esterase isozyme pattern can be useful for screening of genotypes against downy
mildew resistance.
were screened to find out biochemical traits in relation to
downy mildew. Peroxidase activity was determined after 30
and 50 days, whereas phenol, silicon content were estimated
at 30 days stage. Results showed that, at 30 days the peroxidase
activity was lower in resistant entries and higher in susceptible
entries, whereas this trend was reversed at 50 days. Negative
correlation was obtained at 50 days between disease incidence
and peroxidase activity. Phenol content showed positive
correlation with disease incidence but the difference was
non-significant amongst resistant and susceptible entries.
There was a positive relationship between silicon level in
various entries and their degree of disease resistance. In
resistant entry lignin deposition was more in vessel walls,
cortical parenchyma cells and cuticle layer, while it was very
less in susceptible entry at 50 days. Thus, peroxidase activity
and silicon content can be useful traits in relation to downy
mildew in pearl millet.