Browsing by Author "Anu ,Ambadi"

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    Seed pre-treatment with endospore -forming rhizobacteria in Kiriyathu (Andrographis paniculata (Burm.f.) wall. Nees) for enhancing growth and quality
    (Department of Plantation Spices Medicinal and Aromatic Crops, College of Agriculture ,Vellayani, 2024-01-30) Anu ,Ambadi; Sonia, N S
    The study entitled “Seed pre-treatment with endospore-forming rhizobacteria in Kiriyathu (Andrographis paniculata (Burm. f.) Wall. ex. Nees) for enhancing growth and quality” was carried out at the Department of Plantation, Spices, Medicinal and Aromatic Crops, College of Agriculture, Vellayani, Thiruvananthapuram, Kerala during 2021-2023 with the objectives to evaluate the effect of seed treatment with endospore-forming rhizobacteria on seed storage; seed germination; growth promotion and secondary metabolites production in Kiriyathu. The seed of A. paniculata variety Anand Kalmegh 1 (AK-1) was pre-treated with bacterial cultures viz., B. pumilus VLY 17 (T1), B. amyloliquefaciens VLY 24 (T2), B. velezensis PCSE 10 (T3) and bacterial consortium [B. pumilus VLY17+ B. amyloliquefaciens VLY 24+ B. velezensis PCSE 10] (T4) at 1014 cfu mL-1. Seed without bacterial pre-treatment was served as the control (T5). The treated seeds were evaluated during seed storage for bacterial survival. Moreover, the pre-treated seeds were evaluated for seed germination characteristics and planted in polybags for assessing growth and quality. All bacteria species as well as its combination found to survive in the pre-treated seed up to six months after storage. The bacterial count was found to be highest for B. pumilus VLY 17 during 6 MAS (6.66 log cfu g-1). Germination characteristics of bacteria pre-treated seed were found to be superior than the control seed. The Kiriyathu seed pre-treated with B. pumilus VLY 17 exhibited the highest germination percentage (85.00 %), survival percentage (85.00 %), germination index (2.60), shoot length (6.54 cm), root length (5.04 cm), seed vigour index (926.60), allometric index (0.77) and lower mean germination time (3.30 days). Seed pre-treatment with bacteria showed significant improvement in plant growth characteristics viz., morphological, phenological and yield parameters during harvest at 120 DAS compared to the control. B. pumilus VLY 17 pre-treated seed recorded the highest plant height (83.03 cm), number of branches (33.42), number of nodes (472.44), number of flowers (104.00), shoot weight (fresh-120.27 g, dry-38.81 g), whole plant weight (fresh -138.21 g, dry -43.02 g), root length (29.29 cm), seed yield (3.43 g) and thousand seed weight (2.22 g). Also, B. pumilus VLY 17 pre-treatment took lesser days to flower initiation (95.88 days), days to fruit set (16.06 days) and days to fruit maturity (28.25 days) as well as the highest number of fruits (309.44) and fruit weight (fresh 13.54 g). Highest root dry weight (4.01 g) and fruit dry weight (3.95 g) were in combination treatment and B. velezensis PCSE 10 respectively. Seed pre-treatment showed no significant difference for stem girth, root fresh weight and root volume of Kiriyathu plants. Phytochemicals viz., total alkaloids, total flavonoid content, total phenol content, total saponins and cardiac glycosides were found to be superior in Kiriyathu herbage (ethanolic extract) of bacteria pre-treated seed than the control. B. velezensis PCSE 10 pre-treatment recorded highest total alkaloid content, 78.47 µg AE mg-1 whereas highest flavonoid (37.62 µg QE mg-1) and phenol content (349.92 µg GAE mg-1) were observed by B. pumilus VLY 17 treatment. Total saponins content (140.45 µg DE mg-1) was found highest in bacterial combination while the highest cardiac glycosides (169.33 µg DE mg-1) were present in B. amyloliquefaciens VLY 24 treatment. Pharmacological properties of the Kiriyathu herbage ethanolic extract viz., in vitro antioxidant activity and cytotoxicity against liver cancer cell line (HepG2) were highest in B. pumilus VLY 17 seed pre-treatment, 94.00 % DPPH free radicle inhibition and IC50 value, 50.09 µg mL-1 respectively. Kiriyathu seed could be pre-treated with B. pumilus VLY 17 as a liquid spray at 1014 cfu mL-1 concentration for ensuring enhanced seed germination, plant growth, phytochemical quality and in vitro pharmacological properties. The bacteria survival in the pre-treated seed is ensured up to six months after storage under ambient condition.