International Journal of Agroforestry and Silviculture

International Journal of Agroforestry and Silviculture ISSN 2375-1096 Vol. 8 (8), pp. 001-005, August, 2020. © International Scholars Journals

Full Length Research Paper

Response of pearl millet (Pennistetum glaucum) cultivars to post-flowering drought stress

Yalew Addisie* and Gebre-Egziabher Yemane

Department of Biology, College of Natural and Computational Sciences, Mekelle University, Mekelle, Ethiopia.

Accepted 11 August, 2020

Abstract

Two pearl millet (Pennisetum glaucum (L.) R. Br.) cultivars (Dadda and Shella) were evaluated at post-flowering stage for drought tolerance based on morpho-physiological criteria. The experiment was laid down in a randomized complete block design which comprised of a combination of two factors (cultivars and three water stress regimes; (well watered (36%), moderately stressed (21%) and severely stressed (9%)). Data on morpho-physiological variables such as total green leaf area, relative water content, potential quantum yield, root/ shoot ratio and yield per panicle revealed significant (P ≤ 0.05) differences between the cultivars at severely water stress treatment. Dadda showed the maximum relative water content (RWC) (45.70±1.13%) than Shella with the RWC of (32.00±1.06%) under SS. Under SS moisture level Dadda showed the maximum potential quantum yield of 0.77 µmolm^-2s^-1 than Shella, 0.69 µmolm^-2s^-1. Dadda showed better drought stress tolerance than Shella in terns of relative water content, potential quantum yield, yield per panicle and root/ shoot ratio under sever water stress. The analysis of growth revealed the importance of total green leaf area, relative water content, potential quantum yield, yield per panicle and root/ shoot ratio as markers for drought tolerance during post-flowering stage in Pearl millet cultivars.

Key words: Cultivars, morpho-physiological criteria, pearl millet, post-flowering.

International Journal of Agroforestry and Silviculture ISSN 2375-1096 Vol. 8 (8), pp. 001-007, August, 2020. © International Scholars Journals

Full Length Research Paper

Response of green alga ULOTHRIX  ZONATA  to nitrogen and humic substances

Asha Udayamali Meegolle Lokuhewage

Sun Danuku International Co., Ltd, No. 387, Shirakuwa, Sakura – Ku, Saitama – Shi, Saitama-Ken, 338 – 0811 Japan.

E-mail: address:[email protected]. Fax. +81- 48- 816 – 3623.

Accepted 17 June, 2020

Abstract

Nitrogen and phosphorous are essential elements to aquatic biota. Different types of humic substances (HS), such as humic acid (HA) and fulvic acid (FA) have impact on the freshwater nutrients. The aim of the study was to examine how the presence of humic substances may affect nutrient availability to the growth of ULOTHRIX ZONATA (Weber and Mohr) Kutz. Samples were incubated on different nutrient treatments: nutrient sufficient (+NP), nitrogen deficient without HA or FA (-N) and with HA or FA (-NH/-NF) and phosphorous deficient without HA or FA (N) and with HA or FA (NH/NF). The results demonstrated that addition of HA or FA increased the production of Chlorophyll A and cell density as compared with the cultures exposed to nutrients only at the same concentration. U. ZONATA represented the highest growth efficiency (cell density 14.5 x10⁷ cells/ml, determined by counting number of cells per milliliter in suspension of filamentous green alga) under N deficient with HA or FA treatment. During the experiment, whereas the N deficient treatments had the lowest cell numbers (2.2 to 2.5 x 10⁷ cells /ml). It is suggested that HA and FA could be of great importance in the growth of green alga U.

Key words: Fulvic acid, green alga, growth efficiency, humic acid.

International Journal of Agroforestry and Silviculture ISSN 2375-1096 Vol. 8 (8), pp. 001-006, August, 2020. © International Scholars Journals

Full Length Research Paper

Biochemical response of two Atriplex species (Atriplex halimus L. and Atriplex canescens (Pursh) Nutt.) under salt stress conditions

Ouiza DJERROUDI¹*, Samia BISSATI¹ and Moulay BELKHODJA²

¹Laboratoire des Bioressources Sahariennes: Préservation et Valorisation. Université Kasdi Merbah, Ouargla, Algérie.

²Laboratoire de Physiologie Végétale. Université d’Oran, Algérie.

Accepted 10 April, 2020

Abstract

Soil salinization is an environmental problem that many world regions must fight; it is one of the major plants abiotic stress factors. In fact, in addition to mineral imbalance and toxicity of certain ions, salinity causes, in consequence of osmotic pressure increase, water absorption decrease which leads to stress. In the current study, the behavior and response of two Atriplex species, A. halimus L. and A. canescens, (Pursh) Nutt. under effect of high salt concentrations (400 and 600 meq of NaCl + CaCl₂) and seawater at 25, 50 and 100% dilutions, were studied, using proline as metabolic marker in relation to resistance to salinity. Three-month-old Atriplex plants were subject to the various salinity levels. The amount of proline was determined from different plant organs after three weeks stress period. The results revealed a metabolic variability characterized by proline accumulation as function of the species, plant organ, and the concentration and nature of salt treatment. In general, the accumulation of proline within the plant occurs in proportion to the medium salt concentration. Indeed, on one hand, the recorded proline contents show that this accumulation is very important in Atriplex canescens (Pursh) Nutt, compared with Atriplex halimus. On the other hand, these contents are high in leaves of both species in presence of high NaCl + CaCl₂ and seawater concentrations.

Key words: Atriplex, salt stress, proline, tolerance, halophyte.

International Journal of Agroforestry and Silviculture ISSN 2375-1096 Vol. 8 (8), pp. 001-008, August, 2020. © International Scholars Journals

Full Length Research Paper

Effects of NaCl on Na⁺, Cl^- and K⁺ ions accumulation in two sugarcane (Saccharum sp.) cultivars differing in their salt tolerance

Christophe Bernard Gandonou^1,2,*, Fidèle Bada², Simplice Léopold Gnancadja², Jamal Abrini¹ and Nadia Skali-Senhaji¹

¹Laboratoire de Biologie et Santé, Université Abdelmalek Essaâdi, Faculté des Sciences de Tétouan, B.P. 2121 Tétouan, Maroc.

²Laboratoire de Physiologie Végétale, Faculté des Sciences et Techniques (FAST/UAC), 01BP 526 Cotonou, République du Bénin.

Accepted 20 May, 2020

Abstract

The effects of salt on growth and ions accumulation were investigated in two sugarcane (Saccharum sp.) cultivars, CP66-346 (salt-tolerant) and CP65-357 (salt-sensitive). Young plants of these cultivars were exposed to four NaCl concentrations (0, 17, 34 and 68 mM). Na⁺, Cl^- and K⁺ ions concentrations were quantified after 2 weeks of stress. NaCl effect resulted in plant growth reduction in both cultivars but cv. CP66-346 plants were less affected compared to CP65-357 indicating that CP66-346 was more salt-tolerant than CP65-357. Na⁺ and Cl^- concentrations increased significantly in leaves and roots under salinity while K⁺ concentration significantly decreased in both cultivars. The highest accumulation of Na⁺ and Cl^- occurred in young leaves of the salt tolerant cv. CP66-346 coupled with the lowest reduction in K⁺ concentration. These results suggest that the salt tolerance of cv. CP66-346 is closely related to a high accumulation of Na⁺ and Cl^-. ^. K⁺ ions also may play a key role in sugarcane salt tolerance.

Key words: Ions concentrations, sugarcane, Saccharum sp., salt-tolerance.

International Journal of Agroforestry and Silviculture ISSN 2375-1096 Vol. 8 (8), pp. 001-007, August, 2020. © International Scholars Journals

Full Length Research Paper

Expression of novel ascorbate peroxidase isoenzymes of wheat (TRITICUM  AESTIVUM  L.) in response to heat stress

Kumar, R. R.¹*, Goswami, S.¹, Kumar, N.¹, Pandey, S. K.², Pandey, V. C.¹, Sharma, S. K.¹, Pathak, H.² and Rai, R. D.¹

¹Division of Biochemistry, Indian Agricultural Research Institute (IARI), New Delhi, India Pin 110012, India.

²Division of environmental Science, Indian Agricultural Research Institute (IARI), New Delhi, India Pin 110012, India.

Accepted 08 April, 2020

Abstract

Active oxygen species are produced by some of the important organelles like chloroplast and mitochondria through their electron transport chain even under normal environmental condition but the rate of active oxygen species (AOS) production increases many times in response to different abiotic stresses. Plants has antioxidant enzymes system like ascorbate peroxidase (APX), catalase, SOD, GR etc. which helps in reducing the AOS produced inside the plant system in order to protect the key enzymes from AOS. In present investigation, expressions of many new proteins were observed in thermo tolerant (8 in case of C306) and susceptible cultivars (2 in case of PBW343) at different stages in response to heat stress. Isoenzymic profile of APX in response to differential heat shock revealed the expression of 8 APX isoenzymes in C306 (thermo tolerant) compare to 2 in PBW343 (susceptible) cultivars of wheat. A stage specific study revealed the expression of 5 APX isoenzymes at vegetative, pollination, milky dough and seed hardening stages (C306) whereas, 3 APX isoenzymes were observed during milky dough and seed hardening stages in PBW343. It is clear now that high expression of endogenous APX isoenzymes supplements the antioxidant enzyme systems of the plant and protects the plant from oxidative damage in response to biotic and abiotic stresses.

Key words: Heat shock proteins (HSPs), antioxidant isoenzymes, ascorbate peroxidase (APX), active oxygen species, abiotic stress, wheat.

International Journal of Agroforestry and Silviculture ISSN 2375-1096 Vol. 8 (7), pp. 001-009, July, 2020. © International Scholars Journals

Full Length Research Paper

Soil macrofauna indices and their association with physical soil properties under agroforestry systems

Misheck Musokwa^{1, 2*}, Paramu Mafongoya¹, Manqoba Zungu³ and Aleck Kondwakwenda¹

¹University of KwaZulu-Natal, Agricultural, Earth and Environmental Sciences, Bag X01, 3209, Pietermaritzburg, South Africa

²Institute of Natural Resources,P. O Box 100 396, Scottsville, 3209,Pietermaritzburg, South Africa

³Centre for Functional Biodiversity, School of Life Sciences, University of KwaZulu-Natal, Private Bag X01, Scottsville, Pietermaritzburg, 3209.

Received 03 Jun, 2020; Accepted 14 July, 2020; Published 20 July, 2020

Abstract

Agroforestry technologies such as Sesbania sesban or pigeonpea improved fallows have been promoted to restore degraded biophysical soil properties in Sub-Saharan Africa. The objectives of the study were to evaluate the effect of improved fallows on soil macrofauna species indices, abundance of earthworms and related physical soil properties. A randomized complete block design, replicated three times, was used with five treatments (S.sesban, pigeonpea, S.sesban + Panicum maximum, pigeonpea + P.maximum and P.maximum). Soil macrofauna was sampled using 25 × 25 × 25 cm steel monoliths. Aggregate stability was calculated using mean weight diameter. Soil aggregate stability and infiltration rate were significantly different (P<0.05). The highest aggregate stability and infiltration rate were observed in S. sesban as compared to P. maximum.P. maximum + S.sesban (18.89) had the highest soil macrofauna species richness than P. maximum (7.89). Earthworm abundance was highest on S.sesban than other treatments. The highest positive significant correlation was recorded on soil macrofauna species evenness and diversity while the least was observed on aggregate stability and macrofauna species richness. S.sesban or pigeonpea improved fallows is recommended for restoring soil macrofauna and physical soil properties in South Africa.

Keywords: Aggregate stability, agroforestry, improved fallows, pigeonpea, Sesbania sesban, soil macrofauna.