Genome-Wide Association Analysis of Salt-Tolerant Traits in Terrestrial Cotton at Seedling Stage

Soil salinization is the main abiotic stress factor affecting agricultural production worldwide, and salt stress has a significant impact on plant growth and development. Cotton is one of the most salt-tolerant crops. Therefore, the selection and utilization of salt-tolerant germplasm resources and the excavation of salt resistance genes play important roles in improving cotton production in saline–alkali soils. In this study, we analysed the population structure and genetic diversity of a total 149 cotton plant materials including 137 elite Gossypium hirsutum cultivar accessions collected from China and 12 elite Gossypium hirsutum cultivar accessions collected from around the world. Illumina Cotton SNP 70 K was used to obtain genome-wide single-nucleotide polymorphism (SNP) data for 149 elite Gossypium hirsutum cultivar accessions, and 18,430 highly consistent SNP loci were obtained by filtering. It was assessed by using PCA principal component analysis so that the 149 elite Gossypium hirsutum cultivar accessions could be divided into two subgroups, including subgroup 1 with 78 materials and subgroup 2 with 71 materials. Using the obtained SNP and other marker genotype test results, under salt stress, the salt tolerance traits 3d Germination potential, 3d Radicle length drop rate, 7d Germination rate, 7d Radicle length drop rate, 7d Germination weight, 3d Radicle length, 7d Radicle length, Relative Germination potential, Relative Germination rate, 7d Radicle weight drop rate, Salt tolerance index 3d Germination potential index, 3d Radicle length index, 7d Radicle length index, 7d Radicle weight index and 7d Germination rate index were evaluated by GWAS (genome-wide association analysis). A total of 27 SNP markers closely related to the salt tolerance traits and 15 SNP markers closely related to the salt tolerance index were detected. At the SNP locus associated with phenotyping, Gh_D01G0943, Gh_D01G0945, Gh_A01G0906, Gh_A01G0908, Gh_D08G1308 and Gh_D08G1309 related to plant salt tolerance were detected, and they were found to be involved in intracellular transport, sucrose synthesis, osmotic pressure balance, transmembrane transport, N-glycosylation, auxin response and cell amplification. This study provides a theoretical basis for the selection and breeding of salt-tolerant upland cotton varieties.

Allelopathic Effects of Essential Oils on Seed Germination of Barley and Wheat

In this study, we evaluated the allelopathic effects of essential oils (EOs) from six different plant species, namely, lavender (Lavandula angustifolia), hyssop (Hyssopus officinalis), English thyme (Thymus vulgaris), lovage (Levisticum officinale), costmary (Chrysanthemum balsamita), and cumin (Cuminum cyminum), on seed germination and seedling growth of barley (Hordeum vulgare) and wheat (Triticum aestivum). The main constituents of the EOs of L. angustifolia were 47.0% linalool acetate and 28.4% linalool; H. officinalis’ main constituents were 39.8% cis-pinocamphone, 9.8% trans-pinocamphone, 11.4% β-pinene, and 7.5% β-phellandrene; T. vulgaris’ were 38.2% para-cymene, 25.6% thymol, and 13.6% γ-terpinene; L. officinale’s were 64.8% α-terpinyl acetate and 14.7% β-phellandrene; C. balsamita’s were 43.7% camphor, 32.4% trans-thujone, and 11.6% camphene; C. cyminum’s were 49.6% cumin aldehyde, 10.4% para-cymene, 11.6% α-terpinen-7-al, and 9.1% β-pinene. All six EOs exhibited an allelopathic effect and suppressed the seed germination and seedling development of wheat and barley; however, the concentrations that exhibited a suppressing effect were different among the plants. C. cyminum EO completely suppressed both barley and wheat germination at 10-, 30-, and 90-µL application rates, making it the most effective treatment among the tested EOs. C. balsamita’s and H. officinalis’ EOs at 30 and 90 µL application rates completely suppressed barley and wheat radicles per seed, radicle length (mm), seedling height (mm), and germination (%). L. angustifolia’s EOs at 30- and 90-µL and T. vulgaris’ EO at 90 µL application rates also completely suppressed barley and wheat radicles per seed, radicle length (mm), seedling height (mm), and germination (%). C. balsamita’s, H. officinalis’, L. angustifolia’s, and T. vulgaris’ EOs at a 10 µL application rate reduced barley radicle length, seedling height, and % germination relative to the control. Wheat seed germination % was completely suppressed by the application of L. angustifolia’s and T. vulgaris’ EOs at 30 and 90 µL, while T. vulgaris’ EO at 10 µL rate reduced the germination relative to the control. Interestingly, C. balsamita and H. officinalis at 10 µL did not reduce wheat germination; however, they did reduce the number of radicles per seed, radicle length (mm), seedling height (mm), germination (%), and vigor index. Furthermore, L. officinale’s EO reduced the measured indices (radicles per seed, radicle length, seedling height, and vigor index) at the 10, 30, and 90 µL application rates relative to the non-treated control; however, none of the application rates of L. officinale’s EO had a suppression effect on wheat germination. This study demonstrated the allelopathic effects of the EOs of six different herbal plant species on seed germination of barley and winter wheat. The results can be utilized in the development of commercial products for controlling pre-harvest sprouting of wheat and barley. Further research is needed to verify the results under field conditions.

ALLELOPATHIC POTENTIAL OF AQUEOUS EXTRACT OF LEAF AND ROOT SESAME ON SICKLEPOD AND BRACHIARIA SEEDS

Sicklepod is an important weed in Brazil pastures, but control measures are not yet effective. Thus, allelopathy can be an alternative, due to its ecological importance and for being able to provide new structures sources for agrochemicals production. This research aimed to verify the allelopathic potential of sesame (Sesamum indicum L.) on germination and seedling development of sicklepod (Senna occidentalis L.) and brachiaria (Brachiaria brizantha). The treatments were root and leaf extract of sesame, and control (distilled water). Germination percentage, speed of germination, hypocotyl and radicle length were evaluated. Speed of germination, germination percentage and radicle length had no interference from the aqueous extracts. However, in brachiaria these traits had lower values than sicklepod. Hypocotyl length was not influenced by the extracts, however, the leaf extract showed lower growth of this feature. Allelopathy did not affect germination and speed of germination in both species, but interfered in brachiaria development.

Silicon In the Growth of Rice Seedlings Pretreated with Dietholate and Subjected to Cold Stress

Silicon (Si) is an enzyme stimulator that can promote signaling for the production of antioxidant compounds, important in cellular detoxification of excess ROS accumulated during stress. The aim of the study was to evaluate the effects of Si on post-germination rice seeds in the mitigation of cold stress combined with stress induced by seed treatment with the dietholate protector. The experimental design was fully randomized with three replicates and a 3x2x2x4x2 factorial arrangement: three temperatures (5, 10 and 20 °C), two cultivars (IRGA 424 RI and Guri INTA CL), two seed pretreatments (with and without dietholate), four rates of Si (0; 4.0; 8.0 and 16 mg.L-1) and two sources of Si (sodium and potassium metasilicate). Seed pretreatment with dietholate reduced shoot and radicle length, especially at the lower temperatures of 5 and 10 °C. Sodium metasilicate as the source of Si was more efficient in boosting shoot and radicle length, both with and without pretreatment, regardless of temperature. Si was found to attenuate low-temperature stress and the impairment of shoot and radicle growth in rice seedlings grown from seeds pretreated with dietholate.

Evaluation of the drought resistance of pea (Pisum sativum L.) from the VIR collection

Background. As a result of global warming, climate change is now taking place, increasing the frequency and duration of droughts. Therefore, the development of new varieties with an increased drought resistance and adaptation to certain environmental conditions is of primary importance. The aim of this work was to modify the express method of drought resistance evaluation in peas at an early stage of plant growth and development, and to apply this method to test 50 accessions from the VIR global collection.Materials and methods. Drought resistance studies involved garden pea accessions of different eco-geographic origin, which had been previously characterized in field tests in conditions of the Krasnodar Territory in 2017-2019. The roll-ups protocol was used for evaluating early drought resistance in the accessions. The stress intensity was modified by varying the concentration of sucrose in the solution used for growing of pea seedlings. To select an appropriate concentration, an osmotic pressure of 0.5 and 0.7 MPa was applied. As a result, the osmotic pressure of 0.5 MPa was chosen. The diagnostic criterion of the method is the radicle length index (RLI), that is, the ratio of the average radicle length of seedlings against a provocative background to the control values.Results. The osmotically active solution led to significant reduction in the radicle length of pea seedlings. The studied accessions exhibited considerable genetic variability for early drought tolerance, the RLI value varied from 0.28 to 0.88. Sources of high drought resistance during the period of seedling growth have been identified. The correlation analysis showed the absence of a reliable relationship between the RLI and the crop structure indicators (correlation coefficients from r = +0.17 to r = -0.24).Conclusion. By using the method of determining the relative drought tolerance at early stages of pea accessions development, one highly resistant (k-9333 from Morocco) and 10 resistant accessions (k-1495, k-9372, k-9401, k-9418, k-9733, k-9909, k-9934, k-9938, k-10072, and k-10116.) have been identified.

Advanced Application of Electrospun Polycaprolactone Fibers for Seed Germination Activity

The increasing intensity of coronavirus (COVID-19) spreading emphasizes the significant development in home food production to reduce the incoming socioeconomic impact from soaring food prices, supply chain fragility, and severe economic crisis. This preliminary study was initiated to demonstrate the possibility of using electrospun fibers as a potential substrate in the application of seed germination activity. The drive of this preliminary study was to integrate the electrospun nanofiber-based material in exploring the current surge in home food production via seed germination in order to introduce cheap source of food without being distracted by the pandemic impact in general. Mung bean (Vigna radiata L. Wilczek) was chosen as it is easy and fast to sprout. Four samples of poly (ε-caprolactone)- (PCL-) based fibers were prepared by means of electrospinning technique, with the optimized flow rate between 0.05 and 0.20 ml/min at a fixed distance of 10 cm needle tip to collector. Mung bean seeds were allowed to germinate on the fabricated electrospun PCL fibers for 96 hours. Our observations include germination percentage, seedling weight, radicle length, and plumule growth. The highest radicle length and plumule length of seedlings were 27.8 mm and 6.7 mm, respectively. There were no inhibitory effects on seed germination and minimal structural fragmentation of smaller diameter electrospun fibers as revealed by FESEM. These results show that the seeds were able to germinate on electrospun PCL fiber substrate, owing to the properties of high surface area and excellent fluid water uptake of PCL fibers.

The Effect of Beans Position of the Fruit and Liquid Organic Fertilizer on the Cocoa Seedlings

Introduction: This study was aimed to examine the effect of beans positions of the fruit and Liquid Organic Fertilizer (LOF) on the growth of the cocoa seedlings (Theobroma cacao ) in early nurseries. Materials and Methods: This study was conducted at the agricultural experiment land, Universitas Tjut Nyak Dhien, Medan Helvetia District, Medan City from April to June 2020. This study used a Randomized Block Design (RBD) within two factors. The first factor was beans position of the fruit (B0= peduncular, B1= median, B2= apical). The second factor was LOF application (D0= un-treated, D1= 3 ml.l-1, D2= 5 ml.l-1). The variables including radicle length, seedlings height, number of leaves, leaf area, stem diameter, and root fresh weight were then processed using ANOVA and BNT at the rate of 5%. Results: The beans position of the cocoa fruit was an insignificant effect on all parameters of seedlings. LOF application was significant on seedlings height at 4, 6, and 8 weeks after planting (WAP) and also the number of leaves at 8 WAP, but it had an insignificant effect on radicle length, leaf area, stem diameter, and root fresh weight. The interaction of beans position of the fruit and LOF application on the vegetative growth of cocoa seedlings in the early nursery also did insignificant in all parameters of this study.

Evaluation of the effects of 5-fluorouracil and cyclophosphamide on Lathyrus sativus L.

Background The effect of 5-fluorouracil (5FU) and cyclophosphamide (CP) on grass pea (Lathyrus sativus L.) has been studied. Results The effect of the selected drugs on radicle length, colchicine induces polyploidy and in vitro callus growth has been studied (concentration used: 5-Fluorouracil—0.01, 0.1, 1 and 10 mM; Cyclophosphamide—1, 10, 20 and 30 mM). The biochemical studies on superoxide dismutase, catalase and lipid peroxidase activity also studied. Radicle length, polyploidy percentage and callus growth decrease in both the drugs in a dose-dependent manner. The SOD, catalase and LP activity decrease with the increase in drug concentration except for low dose (for 5FU—0.01 mM and 1 mM for CP). Induced polyploidy (Control B) than water germinated seedling (Control A) shows higher enzyme activity but a decrease in the increased dose of drugs. Conclusions The present work has been done to assess the effective potentiality of two anticancerous drugs 5FU and CP with an objective to establish plant system as a model for preliminary screening of anticancerous lead compounds. The result of the present work would pave the way for the screening of unknown lead compounds with the potentiality to act as base analogue and DNA cross-linking drugs. This system is faster, cost-effective and convenient than animal model.

Effects of fresh shoot biomass of siam weed Chromolaena odorata (L.) King and H. Robinson on the germination and growth of okra Abelmoschus esculentus (L.) moench

This study was carried out in the Department of Plant Science and Biotechnology, Federal University Oye Ekiti, Ekiti State. Investigation was carried out on the effects of Fresh Shoot Biomass of Chromolaena odorata on okra Abelmoschus esculentus. For the laboratory experiment, about 5g, 10g, 15g and 20g each of Chromolaena odorata was weighed into plastic bottles each containing 250ml of distilled water for 24 hours. Two millilitres of the leachate was used to water the seeds of okra that was placed in Petri dishes. Each treatment had five replicates that contained four seeds of okra (Abelmoschus esculentus). For the screening experiment, loamy top soil, fresh shoot, stems and leaves of Chromolaena odorata were collected within Federal University Oye Ekiti environment and crushed into smaller bits using mortar and pestle. Three seeds, each of okra that was planted in all the pots. The growth variables considered include radicle length, plumule length, number of roots, for the green house experiment the plant height, leaf area, stem girth, and pod weight were also observed. The leachate of Chromolaena odorata resulted to a reduction in radicle length, plumule length and number of roots. The radicle length of okra treated with leachates of 15g/250ml were adversely affected, while the plumule length of 5g/250ml, 15g/250ml and 20g/250ml greatly decreased compared to the control. The highest decrease in number of roots was noticed in the 15g/250ml concentration. The control plant had the highest plant height increased in a concentration dependent manner with exception of those treated with 200g, the leaf area of the control plant was observed to be lower than all the treatment plants, but it increased in a concentration dependent manner. Also, there was a concentration dependent increase in the steam girth of A. esculentus. The pod weight of the treated plants were lower than the control. The plant treated with 50g highest moisture content, the fat content was higher in the control and plant treated with 50g than the other treated plant. The protein content of the treatment plants was observed to be significantly higher when compared to the control plant. Crude fiber content of the treatment plant was significantly higher than the treatment plants. The ash content of the control was significantly lower than the treated plants, the carbohydrate content of the control plant increased significantly compared to the treatment plant with the lowest at 150g treated plant. The study concluded that the leachate and FSB affected the seed germination, growth and the food content of Abelmoschus esculentus.

Impact of Bisphenol A on seed germination, radicle length and cytogenetic alterations in Pisum sativum L

Bisphenol A (BPA) is a global transpiring pollutant and an endocrine disruptor present in the environment which has a substantial harmful effect on plants. In the present study, its effects on seed germination, radicle length and cytogenetic alterations were investigated in Pisum sativum L root tip cells. Pisum sativum L seeds were germinated after treating with various concentrations of BPA (2 mg/L, 5 mg/L, 10 mg/L, 15 mg/L, 20 mg/L and 25 mg/L) at 24±1°C for 72 hours and the cytogenetic variations were assessed. The investigation showed that BPA reduced the percentage of seed germination, mitotic index, radicle length (at higher concentrations) and instigated a rise in chromosomal anomalies in a dose-related manner. In total, there is an enhanced occurrence of c-mitosis, stickiness, bridges, fragments and laggards in the BPA treated root tip cells of Pisum sativum L seeds.