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Evaluation of morpho-physiological and metal accumulation potential of Salix alba L. and Toona ciliata M. Roemer grown on heavy metal contaminated soils
(Punjab Agricultural University, 2022) Ravneet Kaur; Sharma, Rajni
The present investigations were carried out to study the effect of lead (Pb), cadmium (Cd) and their combinations (Pb+Cd) on morpho-physiological and metal accumulation potential of Salix alba and Toona ciliata during 2020 and 2021. Heavy metals induce negative effect on morphological and biomass attributes of both species, but Toona showed better survival percentage (>95%) than Salix (<55%) even at higher concentrations of Pb300 and Cd25. The accumulation of proline, total soluble sugars, total soluble proteins along with increased antioxidant enzyme activities are responsible to enhance tolerance in both species. On the basis of phytoremediation efficiency evaluation factors such as bioconcentration factor (BCF) and translocation factor (TF), Salix alba can be categorized as excluder plant for Pb and Cd with higher metal accumulation in roots than shoots (BCF>1, TF<1), while Toona ciliata can be categorized as hyperaccumulator with more Pb and Cd accumulation in the shoots than roots (BCF>1 and TF>1). Further, heavy metal translocation and accumulation decreased in combinations as compared to single element application suggesting the antagonistic relationship among both metals. Pb and Cd negatively affect the plant nutrient content either by affecting their translocation or by decreasing nutrient availability in soils. Anatomical studies showed significant alterations in stomatal pore size, stomatal density and trichome density due to heavy metal toxicity in both Salix and Toona. Field emission scanning electron microscopy and energy dispersive x-ray spectroscopy (FESEM-EDS) results confirmed the Pb and Cd accumulation sites in the leaves and root tissues of plants. Fourier transformed infrared (FTIR) spectroscopy analysis revealed that Pb and Cd accumulation in plants induced changes in carboxy, amino, hydroxyl and phosphate groups that ultimately caused alteration in physiological functioning in plants. Conclusively, both Salix alba and Toona ciliata have potential to be used as remediation species for Pb and Cd contaminated soils.
Open Access
EVALUATION OF MORPHO-PHYSIOLOGICAL AND METAL ACCUMULATION POTENTIAL OF Salix alba L. AND Toona ciliata M. Roemer GROWN ON HEAVY METAL CONTAMINATED SOILS
(Punjab Agricultural University, Ludhiana, 2022) Ravneet Kaur; Sharma, Rajni
The present investigations were carried out to study the effect of lead (Pb), cadmium (Cd) and their combinations (Pb+Cd) on morpho-physiological and metal ccumulation potential of Salix alba and Toona ciliata during 2020 and 2021. Heavy metals induce negative effect on morphological and biomass attributes of both species, but Toona showed better survival percentage (>95%) than Salix (1, TF1 and TF>1). Further, heavy metal translocation and accumulation decreased in combinations as compared to single element application suggesting the antagonistic relationship among both metals. Pb and Cd negatively affect the plant nutrient content either by affecting their translocation or by decreasing nutrient availability in soils. Anatomical studies showed significant alterations in stomatal pore size, stomatal density and trichome density due to heavy metal toxicity in both Salix and Toona. Field emission scanning electron microscopy and energy dispersive x-ray spectroscopy (FESEM-EDS) results confirmed the Pb and Cd accumulation sites in the leaves and root tissues of plants. Fourier transformed infrared (FTIR) spectroscopy analysis revealed that Pb and Cd accumulation in plants induced changes in carboxy, amino, hydroxyl and phosphate groups that ultimately caused alteration in physiological functioning in plants. Conclusively, both Salix alba and Toona ciliata have potential to be used as remediation species for Pb and Cd contaminated soils.
Open Access
Identification and characterization of enzyme(s) causing browning of button mushroom, Agaricus bisporus (Lange) Sing.
(Punjab Agricultural University, Ludhiana, 2020) Ravneet Kaur; Sodhi, H.S.
Agaricus bisporus is the most acceptable mushroom in the world but being perishable it loses sheen as fresh produce. Present study has dealt with the enzymes related to browning of button mushroom, namely, tyrosinase (E.C 1.14.18.1), laccase (EC 1.10.3.2), peroxidase (EC 1.11.1.7), phenylalanine ammonia lyase (E.C. 4.3.1.5), lipoxygenase (EC 1.13.11.12) and catalase (EC 1.11.1.6). These were estimated in submerged state and the compost/casing (solid substrate). The enzyme activity of A. bisporus mycelium in broth was found to increase with time and maximum activity was that of peroxidase (7.41U/mg) and laccase (6.05U/mg). Mycelial run in compost indicated maximum specific activity of laccase enzyme (12.3 U/mg) while the activity of the other enzymes was significantly lower. During the pin head stage, there was an increase in the activity of tyrosinase, laccase, peroxidase, PAL, catalase, lipoxygenase enzymes as 17.67, 13.98, 14.67, 4.5, 2.33 and 17.75U/mg respectively. After harvesting during the first flush, tyrosinase activity was reduced up to 12.03 U/mg and remained at par during the second and third flush harvesting. A similar pattern was observed for laccase and PAL. Peroxidase activity showed a decline up to second flush and remained stable thereafter. Catalase activity reduced from the pin head stage to first flush and no significant change in the lipoxygenase activity was observed during reproductive phase of mushroom production. During the postharvest period, the activity of melanin synthesizing enzymes that is tyrosinase, laccase and peroxidase was found to increase with time during storage and maximum increase was that for tyrosinase leading to increase in browning index (BI) value. The activity of the lipoxygenase enzyme increased which led to increased electrolytic leakage and hence lipid peroxidation. During the storage period, there was a decrease in the activity of PAL while the activity of catalase was found to increase. Mushroom washing treatments (KMS, Citric acid and Salicylic acid) and fumigation (cinnamon oil and clove oil) along with packing treatments (polypropylene bags, carton trays with cling film cover and plastic trays with cling film cover) were studied up to 16d at 4 day intervals. The washing treatments using 0.2% KMS, 1% citric acid and 200µmole/L salicylic acid showed a significant decline in the browning associated enzymes and BI in all the packagings during 16d storage. In general mushrooms treated with 200µmole/L salicylic acid and packed in PT showed the best results with minimum BI value (23.09) and tyrosinase activity (27.72 U/mg) at 16th day of storage. Cinnamon oil and clove oil fumigation indicated a gradual decline in activity of melanogenic enzymes and BI with increasing oil concentration up to 40 ppm. Tyrosinase enzyme was purified and found active over pH range 6.4 to 7.2 showing 90% and 88% of the maximum activity at pH 7. The enzyme was stable at a temperature range 25-40°C with maximum activity at 35°C. The kinetic studies of enzyme showed that in case of catechol as substrate, the Km was found to be 0.71 mM with Vmax 2518 µmole/min/ml. In case of L-Dopa from Lineweaver-Burk plot, the Km value was found to be 0.87 mM with Vmax 1714 µmole/ml/min. The SDS-PAGE electrophoresis of the enzyme gave a single prominent band at 43 kDa. FTIR spectra of purified enzyme indicated a secondary structure that reflected the amide I and amide II bands. This study indicated that mushroom browning is a complex process triggered after the harvesting involving the enzymatic reactions. The study of the browning associated enzymes at the different stages of the cultivation and during the storage with different postharvest treatments showed that browning can be decelerated by the postharvest treatments which mainly act by restricting the tyrosinase and related enzymes.
Open Access
Biochemical basis of micronutrient deficiency tolerance in triticale x wheat derivative lines
(Punjab Agricultural University, Ludhiana, 2019) Ravneet Kaur; Bhatia, Surekha
The present study was aimed to investigate the biochemical basis and molecular marker profile of genes associated with micronutrient uptake in parental lines viz rye, triticale (TL 2908, TL 2942), bread wheat lines (PBW 343, PBW550, HD 2967, HD 3086) and durum wheat lines (PDW 233, PDW 291, WHD 943). Five days old seedlings of these parental lines were transferred to three set of treatments (T1-control, T2- micronutrient deficient (stress), T3-with micronutrient supply (alkaline stress pH-9) for 30 days. Rye and triticale lines have longer, hairy and thick roots with high number as compared to bread wheat and durum wheat lines. Roots and shoots of rye and triticale lines accumulated higher fresh/dry weight than bread wheat and durum wheat lines irrespective of treatments. Both stressed conditions caused reduction in roots/shoots fresh weight and dry weight of all parental lines however, rye and triticale lines accumulated greater biomass under alkaline stress conditions on 21 DAT. Rye and triticale lines had higher phytosiderophore content (118 to 498 µmole of Cu equivalents/gFW) than bread wheat (19 to 112 µmole of Cu equivalents/gFW) and durum wheat (6 to 68 µmole of Cu equivalents/gFW) under different treatments during whole period of experiment. In rye and triticale, it was increased from 7 DAT to 21 DAT and decreased afterward on 30 DAT. However, in bread wheat and durum wheat lines, this increase was found only up to 14 DAT. Increase or decrease in release of PSs from roots of parental lines was positively correlated with the higher micronutrient content in roots (r=>0.9) and shoots (r=>0.8) of these lines. Highest micronutrient efficiency was found in rye (73.62-86.08%) followed by triticale lines (70.61-81.06%), bread wheat lines (36.82-66.14%) and durum wheat lines (29.42-62.38%). Further higher activities of SOD, CAT and CA enzymes in rye and triticale lines than bread wheat and durum wheat lines were found which was probably linked with higher micronutrient efficiency corresponding to efficient utilization of micronutrients in rye and triticale lines. Rye and triticale also exhibited higher activities of NAAT and MAS enzymes. Parental lines and triticale X wheat derivative lines were tested for presence of 5R chromosomes using seven 5R chromosome specific markers. Only three markers (SCM 138, KU 140, KU 640) showed expected polymorphism in parental lines were further used to evaluate triticale X wheat derivative lines. Fifteen rye specific primers of Ids3 gene were designed after in-silico sequence analysis. Five primers showed polymorphism in parental lines as well as triticale X wheat derivative lines. Higher release of PSs was estimated from the roots of triticale X wheat derivative lines which were positive for Ids3 and 5R chromosome specific markers. Fourteen triticale X wheat derivative lines with higher PSs under micronutrient deficient conditions, were selected for their further utilization in wheat breeding program for improvement and development of efficient varieties with higher nutritional value.
Open Access
Combining ability analysis for growth and flowering characteristics in pansy (Viola × wittrockiana Gams.)
(Punjab Agricultural University, Ludhiana, 2018) Ravneet Kaur; Dhatt, K. K.
The present studies entitled "Combining ability analysis for growth and flowering characteristics in pansy (Viola × wittrockiana Gams.)" were undertaken at the Floriculture Research Farm of Punjab Agricultural University, Ludhiana during the year 2015-2018. Eight inbred lines of pansy were selected for crossing in half diallel fashion (8x8) to study the general combining ability effects of the parents and specific combining ability of the crosses. Twenty eight hybrids were grown along with their parents in Randomized block design. The results pertaining to the analysis of variance for experimental design and combining ability were highly significant for all the characters. Based on gca effects of parents, the parents Pa-64-1-5-14, Pa-62-4-12-18, Pa-63-1-7-25 and Pa-32-8-7-6 were best general combiners for most of the traits except stalk length and flower size which can be recommended for use in breeding programme to generate genetic variability in desirable direction. Studies on specific combining ability of the crosses indicated that the cross combinations viz.,Pa-64-1-5-14 × Pa-62-4-12-18, Pa-13-1-2-3 × Pa-47-1-3, Pa-11-1-3-7 × Pa-62-4-12-18, Pa-64-1-5-14 × Pa-63-1-7-25, Pa-11-1-3-7 × Pa-64-1-5-14, Pa-32-8-7-6 × Pa-63-1-7-25, Pa-64-1-5-14 × Pa-32-8-7-6 and Pa-11-1-3-7 × Pa-63-1-7-25 were the best specific combiner for most of the vegetative and floral characters viz., plant height, plant spread, branches number, days to flowering, duration of flowering, flowers per plant and pod setting (%). Combining ability analysis revealed that magnitude of gcavariance was greater than sca variance suggesting the predominance of additive gene action for the characters viz., branch count, flower size, days from bud initiation to flowering and flowers per plant. Specific combining ability (sca)variance was greater than gca variance for most of the characters viz., plant height at first flowering (cm), final plant height, plant spread, final plant spread, stalk length, days to flowering, flowering duration and pod setting (%) which indicated predominance of non-additive gene action in their inheritance and heterosis breeding would be the best option for improvement of these traits. Heterosis revealed that majority of the hybrids exhibited heterobeltiosis and mid-heterosis in desirable direction. The hybrids exhibiting high per se performance also showed high mid-heterosis. The hybrids exhibited heterosis over better parent for plant height, plant spread, branches count, stalk length, days from bud initiation to flowering, days to flowering, duration of flowering, flowers per plant were Pa-64-1-5-14 × Pa-63-1-7-25 , Pa-11-1-3-7 × Pa-47-1-3, Pa-32-8-7-6 × Pa-47-1-3, Pa-13-1-2-3 × Pa-47-1-3, Pa-11-1-3-7 × Pa-32-8-7-6, Pa-64-1-5-14 × Pa-32-8-7-6 and Pa-64-1-5-14 × Pa-62-4-12-18. High estimates of PCV and GCV were recorded indicating sufficient variability in the germplasm for most of the characters. PCV and GCV showed a range of variation from 14.25% to 67.50% and 14.10% to 67.29% respectively.High estimates of heritability ranges between 83.55% to 99.37% were obtained for different analysed characters and indicate that though the character was least influenced by the environmental effects. The estimates of genetic advance were varied from 2.25% to 336.80% and from 28.73% to 138.17% for genetic advance as % of mean. High heritability coupled with high genetic advance for the characters viz., number of flowers per plant, branch count and days from bud initiation to flowering were recorded and suggested the role of additive gene action in the inheritance of these characters. Hence, simple selection based on phenotypic performance of these traits would be more effective. The estimates of phenotypic and genotypic correlation revealed that flowers per plant was strongly and positively associated with the characters namely number of branches per plant, plant spread, final plant spread, final plant height and duration of flowering at phenotypic and genotypic level. The result of analysis of variance for F₂ indicated that mean sum of squares due to genotypes were highly significant for all the traits studied. PCV was higher than those of GCV for all the traits which indicated greater genotype x environment interactions for the expression of these characters. The estimates of heritability were more than 72.43 percent for all the characters studied for F₂ genotypes. High heritability along with high genetic advance as % of mean for F₂ population were observed for number of flowers per plant, number of branches per plant and days from bud initiation to flowering hence, amenable for simple selection. The different expected ratios were obtained among twenty eight cross combination of F₂ population of pansy for the inheritance of the flower colour.

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