Root Proliferation Research Articles

Perennial Fodder Crops as a Tool for Soil Carbon Management in Agroecosystems

Carbon sequestration, typically referred to as carbon storage is defined as the “long-term storage of carbon in plants, soils, geologic formations and the ocean, which occurs both naturally and as a result of anthropogenic activities”. With respect to agricultural sector, carbon sequestration is viewed as the capability of agriculture lands to absorb carbon dioxide from the atmosphere. Out of the different ways in play, cultivation of fodder crops turns out to be promising due to its high biomass production, root proliferation, mostly perennial nature, suitability for wastelands and most importantly as the feed for livestock. Restoration of degraded lands, adoption of pasture-based agroforestry systems, inclusion of grasses, sowing of improved forage species, grazing management, nutrient and water management are strategies that aid in improving carbon sequestration in fodder production systems. Perennial fodder grasses and fodder legumes such as alfalfa are excellent for carbon storage as they do not require replanting after each harvest which avoids soil disturbances that usually associate with annual crops. Carbon neutral methods of cultivation is greatly hoped to convert agriculture from a source of carbon to a permanent sink of carbon at a faster pace.

Unlocking nature’s drought resilience: a focus on the parsimonious root phenotype and specialised root metabolism in wild Medicago populations

Abstract Background and aims Crop wild relatives, exposed to strong natural selection, exhibit effective tolerance traits against stresses. While an aggressive root proliferation phenotype has long been considered advantageous for a range of stresses, it appears to be counterproductive under drought due to its high metabolic cost. Recently, a parsimonious root phenotype, metabolically more efficient, has been suggested to be better adapted to semiarid environments, although it is not clear that this phenotype is a trait exhibited by crop wild relatives. Methods Firstly, we analysed the root phenotype and carbon metabolism in four Medicago crop wild relatives adapted to a semiarid environment and compared them with the cultivated M. truncatula Jemalong (A17). Secondly, we exposed the cultivated (probably the least adapted genotype to aridity) and the wild (the most common one in arid zones) M. truncatula genotypes to water deficit. The carbon metabolism response in different parts of their roots was analysed. Results A reduced carbon investment per unit of root length was a common trait in the four wild genotypes, indicative of an evolution towards a parsimonious root phenotype. During the water deficit experiment, the wild M. truncatula showed higher tolerance to drought, along with a superior ability of its taproot to partition sucrose and enhanced capacity of its fibrous roots to maintain sugar homeostasis. Conclusion A parsimonious root phenotype and the spatial specialization of root carbon metabolism represent two important drought tolerance traits. This work provides relevant findings to understand the response of Medicago species roots to water deficit.

Research on the Molecular Mechanisms and Key Gene Discovery in Quercus variabilis Root Pruning Based on Transcriptomics and Hormone Profiling.

Quercus variabilis (Q. variabilis), a significant broadleaf species used in afforestation across high, sandy, and mountainous regions, presents unique challenges for transplantation. This species is characterized by its slow above-ground growth and rapid taproot development, which suppresses the proliferation of lateral and fibrous roots, negatively impacting post-transplant survival. Research indicates that targeted root pruning-specifically, the removal of one-third of the roots-promotes the development of lateral roots in these seedlings. This study involved pruning the root systems of Q. variabilis and assessing the subsequent root development in comparison to an unpruned control group. Our analysis, which included transcriptome sequencing and plant hormone metabolism assays conducted at 2, 12, and 25 days post-pruning, yielded 126.02 Gb of clean data and identified 7662 differentially expressed genes (DEGs). These genes were primarily enriched in the plant hormone signal transduction pathway. Further investigation of this pathway, along with hormone content measurements, elucidated the mechanisms that contribute to enhanced root growth following pruning. Additionally, through a weighted correlation network analysis (WGCNA), we identified 20 key genes that are instrumental in promoting root development in Q. variabilis saplings. This research advances the theoretical framework for forestry seedling production and afforestation, laying the groundwork for scientifically informed vegetation restoration techniques.

Hormopriming and duration of priming interaction on germination, emergence and subsequent growth productivity performance in pechay

This study investigated the potential of Ficus nota water (FNW) as a natural soaking agent to enhance seed germination, emergence, and subsequent growth performance in Pechay (Brassica rapa subsp. chinensis). Utilizing varying FNW concentrations (0%, 50%, and 100%) and seed soaking durations (2, 4, 6 hours), the research aimed to identify optimal treatment combinations for maximizing pre-transplant vigor and post-transplant productivity of Pechy. The results revealed a significant interaction between FNW concentration and soaking time, accelerating germination onset and promoting germination percentage. Notably, the 50% FNW treatment coupled with the 4-hour soaking duration expedited germination by 60% compared to the untreated control. This optimal priming combination also positively influenced seedling height, root proliferation, and biomass accumulation during the pre-transplant nursery stage. Post-transplantation, FNW-primed seedlings exhibited taller stems and broader leaves compared to non-primed controls. However, despite enhancing vegetative growth, priming did not translate into increased biomass yields, suggesting potential trade-offs in resource allocation patterns. The findings highlight the efficacy of FNW in expediting germination and enhancing nursery vigor, while underscoring the need for further investigations into the mechanisms governing the translation of early growth promotion into marketable yields under field conditions. This research contributes valuable insights into the application of natural plant extracts for optimizing seed priming protocols and potentially improving crop productivity.

Change in root morphology, growth, and P transfer: Does foliar P application restrain root P-foraging behavior of Cunninghamia lanceolata seedlings in P-deficient environments?

Although foliar phosphorus application (FPA) is a fertilization method that can rapidly supplement nutrient elements in plants, it remains unclear whether it significantly affects the response strategy of roots under environmental stress. In this study, changes in plant growth, biomass allocation, and P use efficiency (PUE) of Chinese fir in different P environments were analyzed by FPA and root P application (RPA) treatments. The effects of FPA on P-foraging behavior of Chinese fir root system in P-deficient environment were then discussed. The root biomass with RPA was more significant at 0.03-0.25mmol·L-1 P concentrations than that with FPA; however, the PUE was significantly reduced by 28.89–29.41%. With an increase in the P application concentration, under the effect of FPA, the Chinese fir roots mainly reduced root proliferation by decreasing the tip number, surface area and volume but increasing in diameter, as well as the PUE of root, aboveground. As a result, the entire plant was improved. However, the degree of morphological adjustment of the root system was lower than that under RPA. In summary, both FPA and RPA can alleviate P starvation in Chinese fir to a certain extent, thereby improving PUE. Compared with RPA, FPA had a more significant impact on the behavior of Chinese fir roots in sensing and responding to soil P content, and the roots could more quickly sense changes in P content in the body. This mechanism provides valuable insights into the root response strategies of plants in P-deficient environments.

Regulation of maize root growth by local phosphorus availability, sucrose metabolism, and partitioning.

Understanding how maize roots proliferate in phosphorus (P)-rich soil patches is critical for improving nutrient acquisition and crop productivity. This study explores the mechanisms of root adaptation to heterogeneous P availability, focusing on sucrose metabolism and the role of local P signals. A split-root system with chambers of differing Pi concentrations (0 and 500 μM) was used to examine maize root responses. Various physiological and biochemical parameters, including root growth, sucrose partitioning, enzyme activities, and gene expression, were measured to elucidate the underlying mechanisms. Root proliferation, particularly of second-order lateral roots, was markedly enhanced in P-rich patches. Sucrose was preferentially allocated to the Pi-supplied side, as confirmed by Fourier-transform infrared (FTIR) microscopy. Sucrose content in these roots decreased, indicating active metabolism. Higher activities of cell-wall invertase and sucrose synthase were observed in the Pi-supplied roots, supporting enhanced carbohydrate utilization. Local P availability triggers significant adjustments in sucrose metabolism and allocation, enhancing the sink capacity of maize roots in P-rich patches. These changes facilitate efficient lateral root proliferation and Pi utilization, highlighting the critical role of local P signals in nutrient acquisition strategies. This research provides deeper insights into the adaptive responses of maize to heterogeneous P environments, offering potential strategies for improving crop nutrient efficiency.

Developmental responses of roots to limited phosphate availability: research progress and application in cereals.

Phosphorus (P), an essential macronutrient, is crucial for plant growth and development. However, available inorganic phosphate (Pi) is often scarce in soil, and its limited mobility exacerbates P deficiency in plants. Plants have developed complex mechanisms to adapt to Pi-limited soils. The root, the primary interface of the plant with soil, plays an essential role in plant adaptation to Pi-limited soil environments. Root system architecture significantly influences Pi acquisition via the dynamic modulation of primary root and/or crown root length, lateral root proliferation and length, root hair development, and root growth angle in response to Pi availability. This review focuses on the physiological, anatomical, and molecular mechanisms underpinning changes in root development in response to Pi starvation in cereals, mainly focusing on the model monocot plant rice (Oryza sativa). We also review recent efforts to modify root architecture to enhance P uptake efficiency in crops and propose future research directions aimed at the genetic improvement of Pi uptake and use efficiency in crops based on root system architecture.

The soybean NUCLEAR FACTOR-Y C4 and α-EXPANSIN 7 module influences phosphorus uptake by regulating root morphology

Abstract Soybean (Glycine max) is a globally important crop; however, its productivity is severely impacted by phosphorus (P) deficiency. Understanding the transcriptional regulation of low P (LP) response mechanisms is essential for enhancing soybean P use efficiency. In this study, we found that the Nuclear Factor-Y (NF-Y) transcription factor GmNF-YC4, in addition to its previously discovered role in regulating flowering time, possesses other functions in modulating root morphology and P uptake. Knockout of GmNF-YC4 notably boosted root proliferation and P uptake while also influencing the expression of genes related to LP stress. GmNF-YC4 acts as a specific DNA-binding transcriptional repressor, modulating the expression of the soybean α-EXPANSIN 7 (GmEXPA7) gene, which encodes a cell-wall-loosening factor, through direct binding to its promoter region. Further investigation revealed that GmEXPA7 expression is predominantly root-specific and induced by LP. Moreover, overexpression of GmEXPA7 in soybean hairy roots enhanced LP tolerance by stimulating root growth and P uptake. We further screened and obtained more potential target genes of GmNF-YC4 via DNA affinity purification sequencing, including those related to LP stress. These findings underscore the pivotal role of the GmNF-YC4-GmEXPA7 module as a key regulator in mitigating LP stress in soybeans.

Effect of Aloe Vera, Wood Ash, and Indole-Butyric Acid on In-Vivo Macro Propagation of Robusta Coffee Stem Cuttings

Purpose: This study investigated the influence of Aloe Vera, Wood ash and a synthetic growth hormone Indole-butyric acid (IBA) on root and shoot in the proliferation of Coffee Wilt disease-resistant (CWD-R) Robusta coffee stem cuttings. Methodology: Stem cuttings of CWD-R Robusta coffee were treated with five levels of rooting natural substances and IBA independently and in combination. The treated cuttings were propagated in a uniform potting medium under humidity chamber conditions. Data was collected on the number of surviving cuttings, shoot and root number, and root and shoot lengths. At 90 days after planting, data on root proliferation, the number, and lengths of roots were collected and analyzed for variance (ANOVA) using GenStat 11th Edition. Findings: The survival, root, and shoot development were significantly (p<0.05) influenced by the rooting substances applied. A combination of Aloe Vera and IBA, 0.8% IBA, and Aloe Vera gel applied alone gave the highest percentages (90, 70 and 70%, respectively) of stem cuttings that survived to form roots and shoots. A mixture of aloe Vera and IBA, 0.8% IBA, and Aloe Vera gave the highest mean number of shoots and roots per cutting; that is (8.75, 8.5, and 8.5 cm) and (13.87, 12.85 and 12.39 cm) for shoots and roots respectively. Cuttings treated with wood ash and control gave the lowest mean number of shoots and roots that formed per cutting; that is (5.25 and 4.50 cm) and (11.75 and 11.38 cm) for shoots and roots respectively. Unique Contribution to Theory, Practice and Policy: Propagation of Coffea canephora, by stem cuttings can be adequately achieved by using Aloe Vera, IBA, or their mixture, but not with wood ash.

Soil Solution Properties of Tropical Soils and Brachiaria Growth as Affected by Humic Acid Concentration

The soil solution is the compartment where plants uptake nutrients and this phase is in equilibrium with the soil solid phase. Changes in nutrient content and availability in the soil solution can vary among soil types in response to humic acid concentrations, thereby affecting Brachiaria growth. However, there are no studies demonstrating these effects of humic acid application on different soil types and how they affect Brachiaria growth. Thus, the aim of this study was to evaluate the effects of humic acid concentrations (0, 5, 10, 25, and 60 mg kg−1 carbon-humic acid) on Brachiaria brizantha growth and soil solution properties of contrasting tropical soils. Plants were grown for 35 days in greenhouse conditions in pots containing Sandy Entisol, Clayey (Red Oxisol), and Medium Texture (Red-Yellow Oxisol). Soil solution was assessed for pH, electrical conductivity (EC), carbon, and nutrient content. Shoot and root dry matter, as well as macro and micronutrients accumulation in the shoot, were determined. In a soil type-dependent effect, pH, EC, and concentrations of nutrients in solutions changed in response to carbon-humic acid concentration. In the less-buffered soils, Sandy Entisol and Red-Yellow Oxisol, the addition of 30–40 mg kg−1 carbon-humic acid increased root proliferation by 76–89%, while Brachiaria biomass produced in all soils increased by approximately 30%. Levels of carbon in solution were high (>580 mg L−1) and varied depending on the investigated soil type. Though solution carbon contents did not appear to be a driving factor controlling the positive effects of humic acid concentrations on Brachiaria dry matter, there was a direct relationship between other properties and nutrient content in the soil solution, and Brachiaria dry matter production.

Family ties: Root-root communication within Solanaceae

Root–root communication effects on several physiological and metabolic aspects among Solanaceae relatives were studied. We examined cherry (C) and field (F) tomato (Solanum lycopersicum) and bell pepper (B) (Capsicum annuum), comprising three degrees of relatedness (DOR): high (H-DOR; CC, FF and BB), medium (M-DOR; CF) and low (L-DOR; CB and FB). Plants were grown in pairs of similar or different plants on a paper-based and non-destructive root growth system, namely, rhizoslides. Root growth, including the proliferation of fine roots, and respiration increased as the DOR decreased and were highest in paired L-DOR plants, as was shown for root respiration that increased by 63, 110 and 88 % for C, F, and B when grown with B, B and F, respectively. On the other hand, root exudates of L-DOR plants had significantly lower levels of total organic carbon and protein than those of H-DOR plants, indicating different root–root communication between individuals with different DOR. Our findings indicate, for the first time, that carbon allocation to root growth, exudation and respiration depends on the degree of genetic relatedness, and that the degree of relatedness between individual plants plays a key role in the root-root communication within Solanaceae.

Intensification of Rindera graeca transgenic roots proliferation and deoxyshikonin secretion in wave-agitated disposable bioreactor

For millennia, plants have been a source of natural medicines used by humankind. In vitro cultures of plant organs, e.g., transgenic roots, provide a suitable environment for maintaining plant biomass and continuously producing plant-derived bioproducts. The in vitro cultures of plant biomass can be efficiently scaled up using disposable bioreactors with wave-type agitation conditions. The study aimed to investigate the influence of wave-type agitation conditions supported by the WAVE 25 bioreactor on biomass proliferation and secondary metabolite production offered by the in vitro system of Rindera graeca transgenic root culture. Two morphologically different pellets of R. graeca biomass have been observed: highly ramified for cultures performed at ReL < 4000 and compacted for cultures performed at ReL > 5200. The growth of transgenic root biomass cultured in the WAVE 25 bioreactor at ReL = 1325 was over two times higher than for cultures performed in small-scale systems of oscillatory shaken Erlenmeyer flasks.

Full-Length Transcriptome Assembly of Platycladus orientalis Root Integrated with RNA-Seq to Identify Genes in Response to Root Pruning

Platycladus orientalis (P. orientalis) is a common tree used for vegetation restoration in northern China, and its large area propagation helps to improve site conditions. However, under harsh conditions such as poor land, the survival rate of P. orientalis is very low. Numerous studies have shown that root pruning can promote the formation of lateral roots in seedlings, enhancing the roots’ capacity to absorb soil nutrients and water, and thereby improving the survival rate of seedlings. In this study, a one-third root pruning treatment was applied to P. orientalis seedlings, and the whole transcriptome of seedlings subjected to both control (CK) and root pruning treatments was sequenced to analyze their gene expression profiles. This study investigated the regulatory mechanisms of lateral root development in response to root pruning damage at the molecular level. Using nine cells, 15.28 Gb of clean data were obtained, which yielded 101,688 high-quality full-length transcript sequences and 22,955 low-quality full-length transcript sequences after clustering. Redundancy was then removed using CD-HIT, and Illumina RNA-seq sequencing produced 139.26 Gb of clean data. A total of 2025 differentially expressed genes (DEGs) were identified at three time points following root pruning treatment. Enrichment analysis revealed that the peroxidase gene family plays a significant role in lateral root proliferation. Furthermore, the expression levels of the peroxidase gene family were notably upregulated in comparison to the control group. Pathway enrichment analysis identified 22 relevant genes, which appeared to be highly associated with root growth and resilience to stress. Through examining the expression patterns and correlations of these genes, five central genes emerged as key players. The findings of this research suggest that the peroxidase gene family plays a crucial role in the stress response and root development of P. orientalis, providing reference and guidance for root development in other plant species.

Effect of localized fertilizer application on deep root development during early growth in upland rice under upland condition

ABSTRACT The effects of localized fertilizer (LF) application on changes in root system architecture (RSA) of upland rice seedlings under upland condition were evaluated, and root traits important for deep root development were identified using three root box experiments (Exps). Fertilizer was homogeneously mixed and broadcasted on the soil surface in two control treatments, while in three LF treatments, it was point-placed at 2.5, 7.5 and 12.5 cm below the soil surface. Nitrogen (N) fertilizer in Exp. 1, phosphorus (P) fertilizer in Exp. 2 and compound fertilizer with nitrogen, phosphorus and potassium (NPK) in Exp. 3 were used to compare the effects of LF. Localized N and NPK application altered the RSA through root proliferation and increasing root length percentage around the fertilizer-applied area, whereas localized P application had no effect on both root and shoot development. Deep root and shoot development were decreased with localized NPK application compared to homogeneously mixed control treatment but were maintained with localized N application, when applied at deeper soil depths. Furthermore, the increase in deep root length (DRL) was closely related to the increase in both total root length (TRL) and deep root length ratio (DRR). DRR increased with TRL in Exps. 2 and 3, while it was independent from TRL in Exp. 1, suggesting that DRL can be promoted by increasing DRR regardless of TRL. These results showed that localized N application at deeper soil depths could modify RSA of upland rice seedlings grown under upland condition without affecting shoot growth.

Relationship Between Fine Root Biomass and Soil Physico-chemical Properties of Grassland Ecosystem in Bhadrapur Municipality of Jhapa district, Eastern Nepal

This study investigated the distribution of fine root biomass and various soil properties in a grassland ecosystem within Bhadrapur Municipality, Nepal. Soil samples were systematically collected from randomly selected blocks in undisturbed, disturbed, and roadside areas during the late rainy season. Analyses included soil texture, moisture content, temperature, pH, and quantification of fine root biomass (FRB; &lt;5 mm diameter) within the top 15 cm soil depth. Results showed the mean FRB was significantly higher in undisturbed areas (7.77 t/ha) compared to disturbed (7.053 t/ha) and roadside (1.76 t/ha) areas. Across all sites, FRB exhibited a positive correlation with soil moisture content. Soil pH was slightly more acidic in undisturbed versus disturbed and roadside areas. Soil temperature demonstrated a positive correlation with FRB in undisturbed and roadside areas but a negative correlation in disturbed areas. Additionally, FRB negatively correlated with sand content in disturbed and roadside areas. The findings highlight how soil moisture is a key driver of fine root proliferation in this grassland ecosystem. Variations in soil texture, pH, and temperature between sites reveal their influence on root growth dynamics. Understanding these root-soil interactions has implications for sustainable grassland management, biodiversity conservation, and ecosystem resilience under changing environmental conditions.

Species richness and dominant functional groups enhance aboveground biomass, with no effect on belowground biomass in Qinghai-Tibet Plateau's grasslands

Understanding the role of plant diversity in maintaining grassland ecosystem functioning is of great importance in ecological research. Despite decades of research, ecologists have struggled to understand the biodiversity-ecosystem functioning relationships and how the dominance of plant functional groups impacts ecosystem function. In attempting to understand (i) the temporal patterns of above- and below-ground biomass (AGB and BGB) and species richness, (ii) whether species richness is consistently associated with AGB and BGB, and (iii) the relative contributions of plant functional groups (forb, grass, legume, and sedge) in stabilizing ecosystem function, we used biomass productivity data of meadow steppe and alpine meadow in the Qinghai-Tibet Plateau (QTP) for the period 2015–2019. Our results show that AGB for both grasslands increased, but BGB stayed steady over 5 years. The rising tendency of AGB was caused by the upward trend of AGB in forbs and grasses, which are the dominant functional groups in QTP, stressing the importance of dominant functional groups to ecosystem functioning. The biodiversity-ecosystem functioning relationships were significantly positive for AGB, stable for BGB, and negative for the BGB:AGB ratio, which highlights the crucial role of higher species richness in ecosystem functioning. Significant differences in mean species richness among sites (9–19 species in meadow steppe and 8–22 species in alpine meadow) highlight the varying levels of species diversity across sites in the QTP. While 42% of the sites showed stable species richness, the reported increasing trends in species richness at 58% of the sites indicate the potential for ecological changes or processes in these areas. AGB in both grasslands increased, while BGB remained stable with increasing precipitation. The top soil layer (0–10 cm) dominated the observed BGB in both grasslands, as abundant nutrients in the top layer provide favorable conditions for root proliferation. In meadow steppe, AGB formed an isometric relationship with BGB, indicating that AGB increased with BGB. This study concludes that species richness influenced ecosystem functioning, and forbs and grasses dominated biomass productivity, of which the topsoil layer contributed three-quarters of BGB. Our study (i) provides empirical evidence of stable to increasing species richness in both grasslands over 5 years, and (ii) highlights the role of greater species richness in enhancing ecosystem functioning. These findings serve as a scientific reference for policymaking regarding ecosystem stability.

Multi-trait association mapping for phosphorous efficiency reveals flexible root architectures in sorghum

BackgroundOn tropical regions, phosphorus (P) fixation onto aluminum and iron oxides in soil clays restricts P diffusion from the soil to the root surface, limiting crop yields. While increased root surface area favors P uptake under low-P availability, the relationship between the three-dimensional arrangement of the root system and P efficiency remains elusive. Here, we simultaneously assessed allelic effects of loci associated with a variety of root and P efficiency traits, in addition to grain yield under low-P availability, using multi-trait genome-wide association. We also set out to establish the relationship between root architectural traits assessed in hydroponics and in a low-P soil. Our goal was to better understand the influence of root morphology and architecture in sorghum performance under low-P availability.ResultIn general, the same alleles of associated SNPs increased root and P efficiency traits including grain yield in a low-P soil. We found that sorghum P efficiency relies on pleiotropic loci affecting root traits, which enhance grain yield under low-P availability. Root systems with enhanced surface area stemming from lateral root proliferation mostly up to 40 cm soil depth are important for sorghum adaptation to low-P soils, indicating that differences in root morphology leading to enhanced P uptake occur exactly in the soil layer where P is found at the highest concentration.ConclusionIntegrated QTLs detected in different mapping populations now provide a comprehensive molecular genetic framework for P efficiency studies in sorghum. This indicated extensive conservation of P efficiency QTL across populations and emphasized the terminal portion of chromosome 3 as an important region for P efficiency in sorghum. Increases in root surface area via enhancement of lateral root development is a relevant trait for sorghum low-P soil adaptation, impacting the overall architecture of the sorghum root system. In turn, particularly concerning the critical trait for water and nutrient uptake, root surface area, root system development in deeper soil layers does not occur at the expense of shallow rooting, which may be a key reason leading to the distinctive sorghum adaptation to tropical soils with multiple abiotic stresses including low P availability and drought.

Phytoremediation: A Sustainable Approach to Combat Soil Salinity

Soil salinization is a significantconstraint affecting the productivity of agricultural land worldwide. This led to the abandoning of the production of farmcrops on colossalland. Soil salinity inversely affects seed germination and plant growth and influences the plant’s biological activities like photosynthesis, respiration, plant metabolism, enzymatic activities, hormone regulation, etc. Therefore, efforts are being made to bring the saline soil under cultivation by improving itthrough a proper drainage system to drain out the salts orapplying chemical amendments. However, these options are costly and energy-intensive for employment in large areas on a vast scale. In this direction, biologically cost-effective approaches are also being practiced to improve these degraded lands. Phytoremediation, a plant-based approach to improving degraded soil, may be an appropriate option. This is done by the plantation of salt-tolerant plant species, which can remove and leach down excess salts like sodium (Na&lt;sup&gt;+&lt;/sup&gt;) from the soil and enhance calcium (Ca&lt;sup&gt;2+&lt;/sup&gt;) salts through the cation exchange process from the root zone. During this process, remarkable properties like soil-aggregates stability, root proliferation, soil hydraulic properties, and nutrient availability to plants are also improved. Such improvement in soil properties facilitates the cultivation of less tolerant plants and improves the environment in general and the climatic conditions by enhancing carbon sequestration.

Establishment of Efficient Protocols for In Vitro Regeneration of Hyptis Suaveolens (L.) Poit. Using Apical Shoots and Nodal Segments

The present work was undertaken with a view to standardize an efficient protocol for in vitro rapid propagation of Hyptis suaveolens. Shoot apices and nodal segments of H. suaveolens produced multiple shoot buds when cultured on MS medium supplemented with 1.5-3.0 mg/l BAP or Kn in the combinations with 0.5-1.0 mg/l IAA or NAA. Nodal explants exhibited highest proliferation (90%) and gave maximum number of shoots per culture (8.40 ± 0.18) on MS medium fortified with 1.5 mg/I BAP and 1.0 mg/l IAA. The shoot buds were elongated on MS medium fortified with different concentrations and combinations of auxins and cytokinins. Elongated shoot buds were further cultured in rooting media for root induction. One fourth MS medium -without PGR was - proved ·the most effective for - induction and proliferation of roots. The--rooted plantlets ·were 'established in the field through successive phases of acclimation and the survival rate was 70%. The Chittagong Univ. J B. Sci. 8(1&amp;2): 99-105, 2013

An Efficient Micropropagation Protocol For Mucuna Pruriens (L.) Dc.

An efficient protocol was developed for rapid micropropagation of Mucuna pruriens (L.) DC., an important medicinal plant species of Bangladesh. For the purpose, leaf segments, nodal segments and shoot apices of in vitro grown seedlings and cotyledon segments of immature seeds of field grown plants were cultured on agar solidified MS medium supplemented with different combinations of PGRs (Plant Growth Regulators). Only leaf and cotyledon segments produced light green to green friable/ compact callus in some of the media combinations. Combination and concentration of PGRs played important role in induction of such tissue. The induced tissues failed to differentiate on further culture in a wider spectrum of PGR supplemented media. On the other hand nodal segments and shoot apices produced multiple shoot buds when grown on a wide range of PGRs (BAP, NAA, IAA, Kn) supplemented media. Maximum number of multiple shoot buds were produced in medium containing 1.5 mg/l BAP + 1.0 mg/l IAA. The elongated shoot buds on further culture in rooting media produced strong and stout root systems. Half strength MS media fortified with either 1.0 mg/l IAA or 2.0 mg/l IAA was most effective for induction and proliferation of roots. These complete plantlets were successfully acclimatized and established in outside pots through a successive phase of acclimatization. The Chittagong Univ. J. B. Sci.,Vol. 7(1 &amp;2):79-89, 2012.