Informatics Publishing Limited

N. Chandrashekar ¹, K. V. Ravishankar ², R. H. Laxman ², A. Rekha ², V. Swarupa ²

Affiliations
1 Department of Biotechnology, University of Agricultural Sciences, G.K.V.K., Bengaluru (Karnataka), IN
2 Indian Institute of Horticultural Research, Hessaraghatta, Bengaluru (Karnataka), IN

Abstract

Present investigation was carried out to study the physiological and biochemical changes during moisture stress by identifying two contrasting genotypes from earliar studies i.e. M. acuminata. ssp burmaniceoides commonly recognised as 'Calcutta-4' belonging to AA genomic group and 'Bee hee kela' belonging to BB genomic group were used. The per cent reduction in photosynthetic rate (P_N) between control and stressed plants was 45.28 (%) for 'Calcutta-4' and 36.01(%) for 'Bee hee kela', Transpiration rate (E) was 30.24 (%) for 'Calcutta-4' and 22.36 (%) for 'Bee hee kela' and Stomatal conductance (gs) was 60.30 (%) for Calcutta-4 and 56.10 (%) for 'Bee hee kela', indicating BB genotypes are tolerant to water deficit conditions. Leaf water potential (Ø) was higher in 'Bee hee kela' (BB) both in watered (-0.913 MPa) and under stress (-1.518 MPa) situations when compared with 'Calcutta-4' (AA) control (-1.35 Mpa) and stressed (-1.824 MPa) plants. Malondialdehyde content was estimated to be high in 'Calcutta-4' than that of 'Bee hee kela' indicating higher degree of membrane damage in Calcutta-4. The two antioxidant enzymes namely Super oxide dismutase (SOD) and Catalase activities were found to be higher in Bee hee kela stressed samples than 'Calcutta- 4' indicating better oxidative damage withstanding capacity. 'Bee hee kela' (BB) showed higher Ø, gs, and antioxidant enzyme (SOD and Catalase) activities. 'Bee hee kela' genotype is more drought tolerant than 'Calcutta-4'. Identified drought tolerant genotype can be further used as a donor for drought tolerance.

Keywords

Banana, Drought, Photosynthesis, Melondialdehyde, Antioxidants.

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A. N. Ganeshamurthy ¹, T. R. Rupa ¹, Karusala Alivelu ², S. Rajendran ¹, R. H. Laxman ¹, G. Ramanandan ¹, S. Mohapatra ¹, B. Aruna ¹

Affiliations
1 Indian Institute of Horticultural Research, Hessaraghatta Lake Post, Bengaluru 560 089, IN
2 Indian Institute of Oilseeds Research, Rajendranagar, Hyderabad 500 030, IN

Abstract

Sapota fruit tree biomass cannot be estimated using general forest tree allometric equations involving measurement of diameter at breast height (DBH) as grafted sapota tree branches below this height. Therefore grafted sapota trees of commercial orchards require an independent allometric equation for nondestructive estimation of tree biomass. Sapota allometric equations were hence developed with a destructive sampling of grafted sapota trees using parameters other than DBH and compared with other equations developed for grafted mangoes. The selected allometric parameters were significantly related to the age of the trees. The root-to-shoot ratio also differed from those reported for forest trees. The biomass expansion factor by and large attained stability beyond 16 years of tree age. The equations so developed generally fitted the data well, and in most cases, more than 50% of the observed variation in biomass was explained by primary branch girth ´ number of primary branches. There was a good agreement between the observed and the predicted bio­mass using both multiple linear regression and power model equations. Further, our purpose was to see if the grafted mango tree equation can predict sapota tree biomass. The results of this study confirmed that the mango equation equally predicts sapota tree biomass and hence the mango tree allometric equation can also be used for estimating sapota tree biomass efficiently.

Keywords

Allometric equation, biomass expansion factor, grafted trees, mango, sapota.

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