Longest Root Length Research Articles

Assessment of Cold Tolerance in Boro Rice (Oryza sativa L.) Genotypes During Germination for Enhanced Adaptability to Low Temperature Stress

An experiment was conducted to evaluate the cold tolerance ability of ten boro rice genotypes in the laboratory conditions for suitability of growing under low temperature stress. The experiment was laid out in Factorial CRD and the low temperature regimes was provided under controlled environment (Walk-in cold chamber by Saveer Biotech Limited) for germination studies that could maintain the specific low temperature. The experiment was conducted in the Department of Crop Physiology and Agricultural Biotechnology, Assam Agricultural University, Jorhat, Assam, India. The germination tests were conducted under four different temperature regimes where seed germination under ambient (T4=28 ± 0.2oC) was considered as control. Low-temperature treatments were provided by the growth chamber at three different levels of low temperature viz. (T3=10-12°C), (T2=7-9oC) and (T1=5-6°C). Per cent germination, germination index, shoot length, length of longest root and seed vigour index were considered for the study. The germination percent, germination index, shoot length, length of longest root and seed vigour index was recorded highest under ambient condition (T4) irrespective of all the genotypes. Seeds grown under T3 showed considerable germination values only after 28 days of germination studies, whereas T1 and T2 showed no germination. The study revealed that amongst all the ten genotypes, Kanaklata and Sona Mahsuri revealed superior performance in germination percentage, germination index, shoot length, length of the longest root and seed vigour index. In the correlation studies, germination % was significantly correlated with germination index, shoot length, length of the longest and SVI at 5% probability level. GI was also positively and significantly correlated with Shoot length (SL), Length of longest root (LLR) and Seed Vigour Index (SVI). The present study revealed that Sona Mahsuri and Kanaklata was found to be the ideal genotypes for germination under low temperature (10-12oC). Therefore, Farmers growing boro rice under low temperature regimes could take the opportunity of selecting the varieties viz. Kanaklata and Sona Mahsuri for higher yield.

Eco-enzyme and mushroom bag-logs waste stimulate production and nutrients content of celery microgreen (Apium graveolens L.)

Celery microgreen is celery harvested at a young stage, which is a suitable production model to support urban farming. The study aimed to investigate the potential use of eco-enzyme and oyster mushroom media waste (bag-logs waste) on the growth of celery as microgreen. The present study employed a fully randomized factorial design comprising two factors. The first factor was the dosage of eco-enzyme (E): 0.5, 15, and 25 mL L-1 of water, while the second factor was the dosage of bag-log waste (L): 0.50, 100, and 150 g/tray. The variables that were assessed included wet weight, fresh economic weight, longest root length, root volume, moisture content, vitamin C, Mg, and Ca levels. The data were subjected to ANOVA analysis and subsequently followed by the application of the HSD test at a significance level of 5%. The findings indicated that there was a substantial interaction between the eco-enzyme and bag-log waste in all observed parameters. The best treatment was the combination of eco-enzyme at a concentration of 25 mL L-1 and bag-log waste at a rate of 150 g/tray. The eco-enzyme treatment exhibited a significant impact on all observed parameters, with the most effective treatment being the application of 25 mL L-1. The bag-log waste application affected all measured parameters with 150 g/tray yielding the most favorable results. Therefore, eco-enzymes and bag-log waste have the potential as growing media for celery microgreen cultivation.
 Keywords: celery, healthy food, organic farming, urban farming, zero waste

LEADER (Leaf Element Accumulation from DEep Roots): A nondestructive phenotyping platform to estimate rooting depth in the field

AbstractDeeper rooted crops are an avenue to increase plant water and nitrogen uptake under limiting conditions and increase long‐term soil carbon storage. Measuring rooting depth, however, is challenging due to the destructive, laborious, or imprecise methods that are currently available. Here, we present LEADER (Leaf Element Accumulation from DEep Roots) as a method to estimate in‐field root depth of maize plants. We use both X‐ray fluorescence (XRF) spectroscopy and ICP‐OES (inductively coupled plasma optical emission spectroscopy) to measure leaf elemental content and relate this to metrics of root depth. Principal components of leaf elemental content correlate with measures of root length in four genotypes (R2 = 0.8 for total root length), and we use linear discriminant analysis to classify plants as having different metrics related to root depth across four field sites in the United States. We can correctly classify the plots with the longest root length at depth (deeper than 30 or 40 cm) with high accuracy (accuracy >0.6) at two of our field sites (Hancock, WI and Rock Spring, PA). We also use strontium (Sr) as a tracer element in both greenhouse and field studies, showing that elemental accumulation of Sr in leaf tissue can be measured with XRF and can estimate root depth. We propose the adoption of LEADER as a tool for measuring root depth in different plant species and soils. LEADER is faster and easier than any other methods that currently exist and could allow for extensive study and understanding of deep rooting.

A 14-3-3 Protein-Encoding Gene, BdGF14g, Confers Better Drought Tolerance by Regulating ABA Biosynthesis and Signaling

Abscisic acid (ABA), a phytohormone, enacts a cardinal function in coping with abiotic stress. 14-3-3 proteins can interact with ABA-responsive-element-binding transcription factors (ABFs), a chief constituent of ABA signaling, and play critical roles in the dehydration response involving ABA signaling. Meanwhile, whether and how 14-3-3 proteins regulate ABA signaling to respond to aridity stress is yet to be fully investigated. Herein, BdGF14g, a 14-3-3 gene induced by ABA, H2O2, and PEG treatments, was identified in Brachypodium distachyon (B. distachyon). Overexpression of BdGF14g improved drought stress tolerance in tobacco plants, with a higher survival rate, longer root length, enhanced cell membrane stability, and increased antioxidase activity compared with non-transgenic controls in coping with dehydration. Both drought and exogenous ABA treatments resulted in smaller stomatal apertures in BdGF14g-transgenic lines. Additionally, when an ABA biosynthesis inhibitor was added, the better growth statuses, less H2O2 accumulation, and higher activities of catalase and superoxide dismutase under mannitol stress disappeared. Moreover, BdGF14g interacted with NtABF2, upregulated the endogenous ABA content, and enhanced the transcription of ABA-related genes, including NtNCED1, a crucial ABA biosynthesis gene, under drought conditions. In conclusion, BdGF14g acts as a positive factor in the water deficiency response by affecting ABA biosynthesis and signaling in tobacco plants.

Diazotrophic organisms and arbuscular mycorrhizal fungi in the establishment of cassava plants

Cassava is an important food base and an excellent alternative source of carbohydrates, especially in developing countries. As it is an easy-to-manage crop, it can be grown in small areas and does not require high soil fertility. This culture has a symbiotic relationship with arbuscular mycorrhizal fungi (AMF), which expand the extent of the roots by the projection of their hyphae, which favors the absorption of water and nutrients from the soil and with nitrogen-fixing bacteria. The objective of this work was to evaluate the interaction of nitrogen-fixing bacteria with arbuscular mycorrhizal fungi at the initial stage of cassava culture. The following parameters were evaluated: the day of sprouting, plant height, root length, plant volume, colonization rate of mycorrhizal fungi and the genera of arbuscular mycorrhizal fungi. Plants inoculated with AMF and diazotrophic bacteria presented the lowest day of sprouting, the highest plant height and longer root length. Mycorrhizal interactions with and without inoculation with nitrogen-fixing bacteria were classified, and mycorrhizal fungi of the genera Acaulospora, Diversispora, Glomus and Gigaspora were classified.

Effect of Different Concentrations of Auxin Hormone (IBA) Upon Promoting Root Development of Stem Cuttings in the ‘Scented Geranium’, Pelargonium graveolens L

The present investigation entitled “Effect of different concentrations of auxin hormone (IBA) upon promoting root development of stem cuttings in the ‘Scented Geranium’, Pelargonium graveolens L” was carried out at Medicinal and Aromatic Plants Research Station, (MAPRS) Rajendranagar, Sri Konda Laxman Telangana State Horticultural University, Hyderabad during December 2022 to February 2023. The experiments were conducted using a Completely Randomized Design (CRD) with three replications under a shade net house. Each replication consisted of seven treatments, which included a control group and six different concentrations of IBA (500 mg L-1, 1000 mg L-1, 1500 mg L-1, 2000 mg L-1, 2500 mg L-1, 3000 mg L-1). The results indicated, that among the various IBA concentrations tested, specifically IBA @ 2000 mg L-1 for stem cuttings, proved to be more effective than all other treatments in terms of various root parameters. It recorded the minimum days taken for root initiation and also recorded better results for the number of roots per cutting, average length of roots per cutting, length of longest root per cutting, fresh weight of roots per cutting, and dry weight of roots per cuttings.

WRKY Transcriptional Factor IlWRKY70 from Iris laevigata Enhances Drought and Salinity Tolerances in Nicotiana tabacum.

Drought and high salinity greatly affect plant growth and development. WRKY transcription factors play a key role in plant tolerance to abiotic stress, but the functions of WRKYs in the ornamental monocotyledon Iris laevigata remain largely unexplored. In this study, we cloned IlWRKY70 and found that it is a Group III WRKY localized in the nucleus. The expression of IlWRKY70 was induced by NaCl and PEG-6000, which reached peaks (4.38 and 5.65 times) after 3 h and 1 h, respectively. The exogenous overexpression of IlWRKY70 in N. tabacum significantly improved the resistance under NaCl and drought treatments, as evidenced by higher germination rates, longer root lengths, and increased fresh weights compared to those of control plants. In addition, transgenic seedlings showed significantly reduced wilting, higher photosynthetic performance, higher Fv/Fm and chlorophyll content, and lower stomatal conductance. Moreover, transgenic lines showed higher antioxidant enzymatic activities, lower reactive oxygen species (ROS), and lower malondialdehyde contents. Accordingly, we also found higher expressions of antioxidant defense genes, including SOD, CAT, and POD, in transgenic lines compared to controls under salt and drought stresses. Thus, IlWRKY70 enhances the abilities of salt and drought tolerances in plants, at least partially, via ROS regulation and can be used for breeding I. laevigata possessing enhanced salt and drought resistances.

Deficit irrigation strategies (PRD, SDI) and titanium nanoparticles improve water use efficiency and flower quality in greenhouse-grown cut roses

This study explored the use of deficit irrigation techniques for water management in the hydroponic greenhouse cultivation of cut roses. A factorial experiment was conducted using three irrigation treatments: full irrigation (FI), partial root drying (PRD), and sustained deficit irrigation (SDI), and three doses of titanium dioxide nanoparticle foliar application (0, 15, and 30 ppm) as stress alleviation. Results showed that drought stress increased biochemical parameters such as the plants' proline and total phenol content. Compared to SDI treatment, the PRD treatments have an increase in flower number by 40%. The PRD strategy has positive effects on drought tolerance by increasing osmotic and elastic adjustment. Therefore, higher relative water content and longer root length in PRD treatments were observed. Thus, Biomass water use efficiency significantly increased in PRD treatments compared to others. In the PRD treatment, yield WUE increases by 26% and 61% compared to FI and SDI, respectively. The results showed TiO2-NPs positively affected mitigating and even improving some traits in drought stress conditions. These results suggest the superiority of the PRD strategy, which improves growth characteristics and water use efficiency, leading to increased sustainability, reduced environmental impact of greenhouse toxic wastewater, and total profitability of the greenhouse.

Integrating Association Mapping, Linkage Mapping, Fine Mapping with RNA Seq Conferring Seedling Vigor Improvement for Successful Crop Establishment in Deep Sown Direct-Seeded Rice

BackgroundOngoing large-scale shift towards direct seeded rice (DSR) necessitates a convergence of breeding and genetic approaches for its sustenance and harnessing natural resources and environmental benefits. Improving seedling vigour remains key objective for breeders working with DSR. The present study aims to understand the genetic control of seedling vigour in deep sown DSR. Combined genome-wide association mapping, linkage mapping, fine mapping, RNA-sequencing to identify candidate genes and validation of putative candidate genes were performed in the present study.ResultsSignificant phenotypic variations were observed among genotypes in both F3:4:5 and BC2F2:3 populations. The mesocotyl length showed significant positive correlation with %germination, root and shoot length. The 881 kb region on chromosome 7 reported to be associated with mesocotyl elongation. RNA-seq data and RT-PCR results identified and validated seven potential candidate genes. The four promising introgression lines free from linkage drag and with longer mesocotyl length, longer root length, semi-dwarf plant height have been identified.ConclusionThe study will provide rice breeders (1) the pre breeding material in the form of anticipated DSR adapted introgression lines possessing useful traits and alleles improving germination under deep sown DSR field conditions (2) the base for the studies involving functional characterization of candidate genes. The development and utilization of improved introgression lines and molecular markers may play an important role in genomics-assisted breeding (GAB) during the pyramiding of valuable genes providing adaptation to rice under DSR. Our results offer a robust and reliable package that can contribute towards enhancing genetic gains in direct seeded rice breeding programs.

Usage of Machine Learning Algorithms for Establishing an Effective Protocol for the In Vitro Micropropagation Ability of Black Chokeberry (Aronia melanocarpa (Michx.) Elliott)

The primary objective of this research was to ascertain the optimal circumstances for the successful growth of black chokeberry (Aronia melanocarpa (Michx.) Elliott) using tissue culture techniques. Additionally, the study aimed to explore the potential use of machine learning algorithms in this context. The present research investigated a range of in vitro parameters such as total number of roots (TNR), longest root length (LRL), average root length (ARL), number of main roots (NMR), number of siblings (NS), shoot length (SL), shoot diameter (SD), leaf width (LW), and leaf length (LL) for Aronia explants cultivated in different media (Murashige and Skoog (MS) and woody plant medium (WPM)) with different concentrations (0, 0.5, 1, 1.5, and 2 mg L−1) of indole-3-butyric acid (IBA). The study showed that IBA hormone levels may affect WPM properties, affecting the LRL and ARL variables. Aronia explant media treated with 2 mg L−1 IBA had the greatest TNR, NMR, NS, SL, and SD values; 31.67 pieces, 2.37 pieces, 5.25 pieces, 66.60 mm, and 2.59 mm, in that order. However, Aronia explants treated with 1 mg L−1 IBA had the highest LW (9.10 mm) and LL (14.58 mm) values. Finally, Aronia explants containing 0.5 mg L−1 IBA had the greatest LRL (89.10 mm) and ARL (57.57 mm) values. In general, the results observed (TNR, LRL, ARL, NMR, NS, SL, SD, LW, and LL) indicate that Aronia explants exhibit superior growth and development in WPM (25.68 pieces, 68.10 mm, 51.64 mm, 2.17 pieces, 4.33 pieces, 57.95 mm, 2.49 mm, 8.08 mm, and 14.26 mm, respectively) as opposed to MS medium (20.27 pieces, 59.92 mm, 47.25 mm, 1.83 pieces, 3.57 pieces, 49.34 mm, 2.13 mm, 6.99 mm, and 12.21 mm, respectively). In the context of the in vitro culturing of Aronia explants utilizing MS medium and WPM, an analysis of machine learning models revealed that the XGBoost and SVM models perform better than the RF, KNN, and GP models when it comes to making predictions about those variables. In particular, the XGBoost model stood out due to the fact that it had the greatest R-squared value, and showed higher predictive ability in terms of properly forecasting values in comparison to actual outcomes. The findings of a linear regression (LR) analysis were used in order to conduct an efficacy study of the XGBoost model. The LR results especially confirmed the findings for the SD, NS, and NMR variables, whose R-squared values were more than 0.7. This demonstrates the extraordinary accuracy that XGboost has in predicting these particular variables. As a consequence of this, it is anticipated that it will be beneficial to make use of the XGboost model in the dosage optimization and estimation of in vitro parameters in micropropagation studies of the Aronia plant for further scientific investigation.

Genetic characterization of root architectural traits in barley (Hordeum vulgare L.) using SNP markers.

Increasing attention is paid to providing new tools to breeders for targeted breeding for specific root traits that are beneficial in low-fertility, drying soils; however, such information is not available for barley (Hordeum vulgare L.). A panel of 191 barley accessions (originating from Australia, Europe, and Africa) was phenotyped for 26 root and shoot traits using the semi-hydroponic system and genotyped using 21 062 high-quality single nucleotide polymorphism (SNP) markers generated by genotyping-by-sequencing (GBS). The population structure analysis of the barley panel identified six distinct groups. We detected 1199 significant (P<0.001) marker-trait associations (MTAs) with r2 values up to 0.41. The strongest MTAs were found for root diameter in the top 20 cm and the longest root length. Based on the physical locations of these MTAs in the barley reference genome, we identified 37 putative QTLs for the root traits, and three QTLs for shoot traits, with nine QTLs located in the same physical regions. The genomic region 640-653 Mb on chromosome 7H was significant for five root length-related traits, where 440 annotated genes were located. The putative QTLs for various root traits identified in this study may be useful for genetic improvement regarding the adaptation of new barley cultivars to suboptimal environments and abiotic stresses.

MsDjB4, a HSP40 Chaperone in Alfalfa (Medicago sativa L.), Improves Alfalfa Hairy Root Tolerance to Aluminum Stress.

The toxicity of aluminum (Al) in acidic soils poses a significant limitation to crop productivity. In this study, we found a notable increase in DnaJ (HSP40) expression in the roots of Al-tolerant alfalfa (WL-525HQ), which we named MsDjB4. Transient conversion assays of tobacco leaf epidermal cells showed that MsDjB4 was targeted to the membrane system including Endoplasmic Reticulum (ER), Golgi, and plasma membrane. We overexpressed (MsDjB4-OE) and suppressed (MsDjB4-RNAi) MsDjB4 in alfalfa hairy roots and found that MsDjB4-OE lines exhibited significantly better tolerance to Al stress compared to wild-type and RNAi hairy roots. Specifically, MsDjB4-OE lines had longer root length, more lateral roots, and lower Al content compared to wild-type and RNAi lines. Furthermore, MsDjB4-OE lines showed lower levels of lipid peroxidation and ROS, as well as higher activity of antioxidant enzymes SOD, CAT, and POD compared to wild-type and RNAi lines under Al stress. Moreover, MsDjB4-OE lines had higher soluble protein content compared to wild-type and RNAi lines after Al treatment. These findings provide evidence that MsDjB4 contributes to the improved tolerance of alfalfa to Al stress by facilitating protein synthesis and enhancing antioxidant capacity.

Root Parameter Investigation in Standardized Media for Bougainvillea (Bougainvillea comm. Ex Juss.) Propagation

The study was conducted in Completely Randomized Design (CRD) with 16 treatments and 5 replications comprising of soilless media and biofertilizer Azotobacter. The present experiment entitled “Standardization of media for propagation of Bougainvillea (Bougainvillea comm. Ex Juss.)” was carried out at Horticultural nursery, College of Agriculture, IGKV, Raipur, (C.G) during the year 2019-20. All of the media treatments compared to the control had better vegetative and rooting qualities. Soil + Sand + Cocopeat had the highest sprouting rate and survival percentage of all the media treatments tested. All other Root attributes viz. The minimum days to rooting (144.80), The longest root length (6.08), highest number of roots per cutting (63.54). The most cuttings that could successfully take root (24.00) were found to be idealistic in media including soil, sand, and cocopeat. The results showed that all increasing media treatments had a substantial impact on all variables related to Bougainvillea development, including shoot and root growth. The results showed that the development of Bougainvillea as well as all the growing media treatments had a significant impact on all the characters' associated root growth. The maximum overall production cost has been seen in T6 (Soil + Sand + Cocopeat) and the least production cost in T13 (Soil + Azotobacter). Combination of rooting media has been beneficial to significantly increase the vegetative growth parameters and economics as compared to control in Bougainvillea.

Selection and Molecular Characterization of Promising Plum Rootstocks (Prunus cerasifera L.) among Seedling-Origin Trees.

The plum (Prunus cerasifera Ehrh) has been used worldwide both as a genetic source for breeding new rootstocks and as clonal rootstock for many Prunus species. Considering situations where wild relatives of plums are endangered, in-depth characterization of rootstock traits of genetic diversity of plum germplasm of Turkey with many ecogeographical locations is crucial. In the present study, therefore, three steps were followed for the selection of rootstock candidates among the plum germplasm grown in the Middle Euphrates. This region is characterized by an extremely hot climate with extremely warm summers and very low precipitation in summers. Initially, 79 rootstock candidates were selected based on rootstocks traits, and Myrobalan 29C was also used for the control rootstock in all steps. Hardwood cuttings were taken from each rootstock candidate, and after the rooting process in rootstock candidates, 39 rootstock candidates outperforming other candidates were selected according to root characteristics. Based on rooting ability, forty rootstock candidates with the longest root length below 33.50 mm, root number below 3.00, and rooting cutting number below 30.00% were eliminated. The second step of the study focused on the dwarfing characteristics of 39 rootstock candidates, and 13 and Myrobalan 29C out of 39 rootstock candidates' dwarfing traits showed value higher compared to the other 26 rootstock candidates. Results indicated that the vigor of rootstock candidates was usually found to be strong (26), intermediate (4), and weak (9). Moreover, 13 out of 39 rootstock candidates' dwarfism trait was better than the other 26 rootstock candidates. In Step 3, some morphological, physiological, and molecular evaluations were conducted in 13 rootstock candidates and the Myrobalan 29C clone, and there were significant differences between both rootstock candidates and the parameters evaluated. PCA has also been indicated that the reference rootstock Myrobalan 29C was grouped with 63B62, 63B69, and 63B14. The highest genetic similarity was found between 63B11 and 63B16, as well as between 63B76 and 63B66, while the lowest genetic similarity was observed between 63B72 and 63B61 candidates. Overall, the findings presented here provide valuable information about the level of rootstock candidates that could potentially be superior among previously uncharacterized plum cultivars in this plum-growing region of Turkey.

The sensitivity of radish cultivars to high temperatures during germination and seedling growth stages

A laboratory experiment was conducted at constant temperatures of 20, 23, 26, 29, 32, 35, 38, and 41℃ to identify the response of six radish cultivars with different root sizes and colors to high-temperature stress during germination, emergence, and early seedling growth stage. Also, the optimal temperature was determined by calculating the relationship between seedling length and temperature via a polynomial regression model. The results showed that no seed germination was detected at 41℃, while emergence and seedling growth were not observed at 38℃ and above. Similar germination percentages, mean germination time, and germination index were obtained between 20℃ and 35℃. The root length reduced at 32℃ and it was more sensitive to high temperatures than shoots because the root/shoot length ratio showed a decreasing trend by increasing temperatures and longer root length was recorded at lower temperatures than 32℃. There were genotypic variations among radish cultivars for temperatures and ‘Kırmızı İnci’, ‘Beyaz İnci’, and ‘Siyah İnci’ produced a better performance than the others under high temperatures. The regression analysis predicted the optimal temperatures as 21.5℃ and 22.6℃ for root and shoot length, respectively. This study indicates that high temperatures inhibited seedling growth rather than seed germination performance of radishes.

In Vitro Propagation of Philodendron erubescens ‘Pink Princess’ and Ex Vitro Acclimatization of the Plantlets

This study describes the in vitro propagation and ex vitro acclimatization of Philodendron erubescens pink princess, one of the most popular ornamental variegated foliage plants. For shoot proliferation, the protocorm-like bodies of the Philodendron pink princess were cultured on solid Murashige and Skoog (MS) media supplemented with 6-benzylaminopurine (BAP) and 1-naphthaleneacetic acid (NAA) at different concentrations. The results revealed that supplementation with BAP alone at a concentration of 1.0 mg/L yielded the maximum number of shoots and leaves. Furthermore, the application of BAP at 1.0 mg/L significantly enhanced the shoot proliferation of Philodendron pink princess when grown in liquid MS medium, yielding 11.2 shoots/explant and 4.7 leaves/explant. When the established microshoots were subjected to root induction using solid MS media supplemented with different kinds and concentrations of auxins, indole-3-butyric acid (IBA) at 3 mg/L resulted in the highest number of roots (3.2 roots/explant) and longest root length (1.9 cm). Three supporting materials, i.e., peat moss, vermiculite, and perlite, were used as planting media for the ex vitro acclimatization of the Philodendron pink princess plantlets. The results demonstrated that the in vitro plantlets acclimatized and exhibited a relatively high survival frequency in all planting media without morphological abnormalities. Peat moss outperformed all other types of planting media in terms of sustaining the vegetative growth of the plantlets. In the future, the approach established in this study could be employed for the extensive production of Philodendron pink princess.

Standardization of growing substrate for multiplication of guava (Psidium guajava) through cuttings

Experiments under the polyhouse were conducted for two consecutive years (2021 and 2022) at Sher-e-Kashmir University of Agricultural Sciences and Technology of Jammu (SKUAST-J), Jammu and Kashmir to evaluate the effect of different growing substrates on guava (Psidium guajava L.) multiplication through cuttings. Twelve substrate combinations were tried in polybags and polytrays under a polytunnel in a polyhouse provided with mist irrigation. The study revealed a positive effect of different growing substrates on growth parameters and successful propagation of guava cuttings. The perusal of the pooled data revealed that T9 was the most effective growing substrate which recorded maximum rooting percentage, survival percentage, plant height, fresh and dry weight, the diameter of thickest sprout, shoot length, length of longest root, leaf area, and the number of roots, shoots, leaves per longestshoot along with minimum mortality percentage and days to first sprouting. However, some growth parameters such as stem thickness, chlorophyll percentage, number of sprouts, sprouted cuttings, and leaves of planted guava cuttings yielded the best results in T10. Cuttings grown in topsoil only without any growing substrate (T12) provided the least values of all the growth parameters of guava cuttings.

The effects of growth regulatory agents in varying doses on Lavandula angustifolia and Lavandula × intermedia species in different rooting media

Lavender is a valuable ornamental and aromatic plant species with several applications, including food additives, cosmetics, perfumes, medicine, and aromatherapy, owing to its antimicrobial, antibacterial, antiviral, and antioxidant properties, as well as its pleasant odor. The purpose of this study was to determine the rooting capability of lavender species (Lavandula angustifolia and Lavandula × intermedia) in different media (peat, perlite, peat+perlite) and different doses of indole-3-butyric acid (IBA) (1000, 1500, and 2000 ppm) on cuttings. After 5 seconds in the (IBA) solution, the cuttings were planted in various rooting media in the greenhouse environment. The highest rooting rate, 93%, was obtained from 2000 ppm IBA application in peat+perlite (1:1) medium, whereas the lowest rooting rate, 13%, was obtained from Lavandula angustifolia species from control application in peat media. In a peat+perlite (1:1) medium with 1500 ppm, the longest root length was 13.16 cm. IBA application Lavandula angustifolia species, the lowest root length in Lavandula × intermedia cuttings were 2.7 cm from control application in perlite medium. Lavandula × intermedia cuttings in peat medium produced the best results in terms of root number (3.36 pcs/cuttings), while Lavandula × intermedia cuttings in perlite medium produced the lowest root number in the control application. In terms of viability rate, both species received high values, with the lowest viability rate obtained from the control application in perlite medium with 80% in Lavandula angustifolia species.

The Effect of Hormone Types, Concentrations, and Treatment Times on the Rooting Traits of Morus 'Yueshenda 10' Softwood Cuttings.

Enhancing the capacity of fruit trees to propagate via cuttings is an important endeavor for the high-quality development of the fruit industry. Optimizing the conditions for the cutting propagation of mulberry seedlings is an important factor that influences the industrial production of this plant; however, the currently used mulberry breeding technology system is not mature. In this experiment, an orthogonal design was used to intercept semi-woody shoots of Yueshenda 10 as cuttings and set different hormone concentrations (200, 500, 800, and 1000 mg/L), different hormone types (NAA, IBA, IAA, and ABT-1), and different soaking times (10, 30, 60, and 120 min) for cuttings. The effects of the three factors on the rooting of mulberry cuttings were investigated by soaking the cuttings in clean water for 10 min as a control. The results showed that the primary and secondary order of the three factors affecting the rooting rate of cuttings was hormone concentration > hormone type > soaking time, and the concentration of exogenous hormones had a significant impact on all rooting indicators (p < 0.05). In addition, the rooting rate (66.24%), average number of roots (7.54 roots/plant), and rooting effect index (4.23) of Yueshenda 10 cuttings reached the optimal level when soaked with 800 mg/L ABT-1 for 30 min. The longest root length (10.20 cm) and average root length (4.44 cm) of cuttings achieved the best results when soaked with 800 mg/L NAA for 60 min and 500 mg/L NAA for 30 min, respectively. On balance, it is considered that the preferred solution is to soak the cuttings of Yueshenda 10 with 800 mg/L ABT1 solution for 0.5 h.

Multigenerational effects of microplastic fragments derived from polyethylene terephthalate bottles on duckweed Lemna minor: Size-dependent effects of microplastics on photosynthesis

The 2019 global coronavirus disease pandemic has led to an increase in the demand for polyethylene terephthalate (PET) packaging. Although PET is one of the most recycled plastics, it is likely to enter the aquatic ecosystem. To date, the chronic effects of PET microplastics (MPs) on aquatic plants have not been fully understood. Therefore, this study aimed to investigate the adverse effects of PET MP fragments derived from PET bottles on the aquatic duckweed plant Lemna minor through a multigenerational study. We conducted acute (3-day exposure) and multigenerational (10 generations from P0 to F9) tests using different-sized PET fragments (PET0–200, < 200 μm; PET200–300, 200–300 μm; and PET300–500, 300–500 μm). Different parameters, including frond number, growth rate based on the frond area, total root length, longest root length, and photosynthesis, were evaluated. The acute test revealed that photosynthesis in L. minor was negatively affected by exposure to small-sized PET fragments (PET0–200). In contrast, the results of the multigenerational test revealed that large-sized PET fragments (PET300–500) showed substantial negative effects on both the growth and photosynthetic activity of L. minor. Continuous exposure to PET MPs for 10 generations caused disturbances in chloroplast distribution and inhibition of plant photosynthetic activity and growth. The findings of this study may serve as a basis for future research on the generational effects of MPs from various PET products.