Number Of Basal Roots Research Articles

Principal Component Analysis and Clustering of Cassava Germplasm based on N and K Efficiency

The present study was undertaken at ICAR-CTCRI, Sreekaryam to identify and group N and K efficient genotypes from a pool of released varieties, pre-breeding lines and elite landraces of cassava during 2021-2022. Thirty genotypes of cassava were evaluated for their diversity based on N and K efficiency along with some of its contributing plant characters using statistical tools like principal component analysis, and dendrogram clustering. The variation existing among the selected genotypes was observed through PCA, where the first six principal components accounted for nearly 81% of the total variability. Characters like tuber yield, plant height, stem girth, tuber length and tuber girth contributed to the greater variability among the genotypes. The dendrogram analysis classified the genotypes into six clusters based on the 18 parameters contributing to nutrient use efficiency. The proportion of the variance accounted by these clusters came up to the extent of 50% displaying the association of the genotypes with similar characters in these clusters. These analyses helped to realize the wide range of variability existing among the selected genotypes for the 18 characters studied. A simple correlation was also worked out between N and K use efficiency with root traits, which revealed that characters such as weight of storage roots, number of storage roots, and number of basal roots showed a positive correlation with both N and K use efficiency in cassava.

Comparative phenomics of root architecture and anatomy in Phaseolus species

Comparative phenomics of root architecture and anatomy in <i>Phaseolus</i> species

Characterization of Common Bean (Phaseolus vulgaris L.) Genotypes for Drought Tolerance

Background: Drought is a major constraint affecting the seed yield of common bean in smallholder farmers’ fields in Malawi. Therefore, there is a need to develop genotypes that can perform well under drought conditions. The study was conducted to assess the variability of common bean genotypes under stressed and optimum soil moisture conditions. Methods: Forty-three common bean genotypes were evaluated under low and optimum soil moisture in a split-plot pot experiment in 2017. Data were collected at flowering stage on five root traits and seed weight. Result: Highly significant (P less than 0.01) differences were observed among the genotypes and the genotype × water treatment interactions for the root traits and seed weight. Water stress increased hypocotyl root number, basal root number and basal root growth angle by 127.1, 11.3 and 46.1% respectively, while hypocotyl root length, basal root whorl number and seed weight were reduced by 7.1, 1.9 and 9.4% respectively. Broad sense heritability and genetic advance (%) was highest for hypocotyl root length. Genotypes CER-78, SAB-560 and SER-125 were considered tolerant to soil moisture stress and should therefore be tested in various drought conditions for release and used for genetic enhancement focusing on root traits and seed yield.

Phenotyping cowpea for seedling root architecture reveals root phenes important for breeding phosphorus efficient varieties

AbstractCowpea (Vigna unguiculata L. Walp.) is a key climate‐resilient legume for food security, especially in sub‐Saharan Africa. Cowpea yields are limited by edaphic stresses including drought and low phosphorus (P) availability. Identifying genotypes with advantageous root phenotypes can facilitate breeding for improved yield in marginal environments. We evaluated 50 elite genotypes from African and U.S. sources for seedling root architecture and root hair length and density. Significant genotypic variation was detected for all phenes, and high heritability was observed for architectural phenotypes including primary root length (77%), basal root number (72%), and taproot branching density (67%). Moderate heritability was detected for root hair length and density among different root classes (34 to 63%), which were positively associated with each other. Principal component analysis identified three clusters, primarily defined by seed dimension and seedling root architecture. Genotypes were identified with longer root hairs (TVu‐7778, Vita7, and Sanzi) and longer taproots (IT96D‐610, IT98K‐111‐1, and IT97K‐499‐35), as potential parents. Root phenotypes, grain, and fodder yield were assessed on a subset of 20 genotypes under contrasting P availability in the field. Some seedling root phenotypes were significantly related to mature plant dry fodder weight (taproot hair density) and to grain yield (lateral root hair density) under low P. Root hairs are positively related to plant productivity under low P. We suggest selection for longer primary roots, as more basal and lateral root roots may be beneficial for cowpea in drought and low P environments. These findings suggest seedling root phenotypes can support cowpea breeding for suboptimal environments.

Synerging of Root Traits and Agronomic Practices in Common Bean Production Improvement under Acidic Soil

The most challenging in twenty first century is the cause and consequences of Climate change and variability. It is hastening frequently by over population more in developing countries. Thus, it is affected several sectors, while Agriculture is the most vulnerable for climate change. As a result both biotic and abiotic factors are bottle neck for food security and sustainability. From abiotic factor, soil acidity is the frequently observed at area where received intensive rainfall due to top soil and metallic elements washed out. Soil acidity is arsenic, and causes abortion of expected production, especially susceptible crops such as Common bean. To overcome this problem, agronomic practices such as lime application, soil conservation techniques and appropriate root traits were reported. Root system architectures traits such as higher basal root number between 12 to 16, basal root whorl number of around 4, and shallow root angle of less than 15° were reported suitable to withstand soil acidity. Agronomic practices alone reported as it is tedious and also difficult to get complete genotypes with full of desired acidity resistance root traits. Hence several reported explained that using the desired root traits for acidity resistance genotypes and important agronomic practices obtained more valuable results as form of integration. Therefore, using the appropriate root traits and agronomic practices support with each other to reduces the syndrome of soil acidity impacts.

Root Crown Response to Fungal Root Rot in Phaseolus vulgaris Middle American × Andean Lines

Fusarium root rot (FRR) is a global limiter of dry bean (Phaseolus vulgaris L.) production. In common bean and other legumes, resistance to FRR is related to both root development and root architecture, providing a breeding strategy for FRR resistance. Here, we describe the relationships between root traits and FRR disease symptoms. Using "shovelomics" techniques, a subset of recombinant inbred lines was phenotyped for root architecture traits and disease symptoms across three Michigan fields, including one field with artificially increased Fusarium brasiliense disease pressure. At the early growth stages, stem diameter, basal root number, and distribution of hypocotyl-borne adventitious roots were all significantly related to FRR disease scores. These results demonstrate that root architecture is a component of resistance to FRR in the field at early growth stages (first expanded trifoliate) complementing previous studies that evaluated root traits at later developmental stages (flowering, pod fill, etc.). Correlation matrices of root traits indicate that resistant and susceptible lines have statistically different root systems and show that basal root number is a key feature in resistant root systems while adventitious root distribution is an important feature in susceptible root systems. Based on the results of this study, selection for increased basal root number, increased adventitious root number, and even distribution of adventitious roots in early growth stages (first expanded trifoliate) would positively impact resistance to FRR.

Seedling root architecture and its relationship with seed yield across diverse environments in Phaseolus vulgaris

Seedling root phenotypes may have important impacts on fitness and are more easily measured than mature root phenotypes. We phenotyped the roots of 577 genotypes of common bean (Phaseolus vulgaris), representing the bulk of the genetic diversity for recent cultivars and landraces in this species. Root architectural phenotypes of seedlings germinated for nine days were compared to root architectural phenotypes in the field as well as seed yield across 51 environments with an array of abiotic stresses including drought, nutrient deficiency, and heat, as well as non-stress conditions. We observed repeatability ranging from 0.52–0.57 for measures of root phenotypes in seedlings, significant variation in root phene states between gene pools and races, relationships between seedling and field phenotypes, and varying correlations between seedling root phenes and seed yield under a variety of environmental conditions. Seed yield was significantly related to seedling basal root number in 22% of environments, seedling adventitious root abundance in 35% of environments, and seedling taproot length in 12% of environments. Cluster analysis grouped genotypes by their aggregated seedling root phenotype, and variation in seed yield among these clusters under non-stress, drought, and low fertility conditions was observed. These results highlight the existence and influence of integrated root phenotypes for adaptation to edaphic stress, and suggest root phenes have value as breeding targets under real-world conditions.

Substrates on the cuttings rooting of black pepper genotypes

The soil in the production of clonal seedlings of black pepper (Piper nigrum L.) contributes to fusarium and nematodes infestation in commercial crops, and thus the usage of alternative substrates might be a preventive control measure against these pathogens. The aim of this study was to investigate the rhizogenic behavior of the cultivars Bragantina, Iaçará and Guajarina of black pepper in different substrates. The experimental design was in randomized blocks in a 3x4 factorial design (cultivars: Bragantina, Iaçará and Guajarina x substrates: soil + organic compound (18%), vermiculite, carbonized rice hulls and commercial substrate), with four replications of 16 cuttings each. The evaluated characteristics were: survival (%); rooting (basal or nodal) (%); nodal rooting (%); basal rooting (%); number of nodal roots; number of basal roots; total number of roots; length of the largest nodal root (cm); basal root length (cm); nodal root volume (cm3); basal root volume (cm3); Total root volume (cm3); nodal root dry mass (mg); basal root dry mass (mg) and the total root dry mass (mg). There are differences within black pepper cultivars as to the characteristics related to the root system. The vermiculite substrate was the most suitable, and carbonized rice hull is not recommended for the adventitious rooting of cuttings of cultivars Bragantina, Iaçará and Guajarina.

Natural variation in common bean (Phaseolus vulgaris L.) for root traitsand biomass partitioning under drought

The present study was undertaken to assess the response of common bean under drought in respect of root traits and biomass partitioning in fifteen common bean genotypes. The basal root whorl number and the number of basal roots was highest in case of WB-185 and lowest in case of SR-1, whereas, the basal root growth angle was highest in case of WB-258 and lowest in case of WB-249. Rooting depth measured as the length of longest root harvested was highest in case of WB-6 (66.2) while as lowest value was recorded for WB-112 (20.4). Dry root weight was highest in case of WB-216 (0.45) and lowest value was recorded for WB-341 (0.22). Similarly leaf biomass was highest in case of WB-6 (0.58) followed by WB-216 (0.58) and the lowest value recorded for WB-1186 (0.12). Shoot dry weight was highest for WB-6 (0.55) followed by WB-216 (0.44) and the lowest value recorded for WB-1186 (0.118). Pod dry weight was highest for WB-489 (2.28) followed by WB-216 (2.19) and the lowest value recorded for WB-83 (0.68).489. Root biomass proportion was highest for WB-195 (18.34) and lowest for WB-489 (10.00). Similarly leaf biomass to total biomass was highest in case of WB-83 (23.19) whereas lowest value was recorded for WB-1186 (7.60). Highest stem biomass proportion was recorded for Arka Anoop (19.19) and the lowest value was recorded for WB-1186 (7.591). Biomass allocation to pods was highest in case of WB-489 (69.92) followed by WB-1186 (68.69) whereas lowest value was recorded for WB-83 (45.40).

Legume shovelomics: High—Throughput phenotyping of common bean (Phaseolus vulgaris L.) and cowpea (Vigna unguiculata subsp, unguiculata) root architecture in the field

Low phosphorus (P) availability and drought are primary constraints to common bean and cowpea production in developing countries. Genetic variation of particular root architectural phenes of common bean is associated with improved acquisition of water and phosphorus. Quantitative evaluation of root architectural phenotypes of mature plants in the field is challenging Nonetheless, in situ phenotyping captures responses to environmental variation and is critical to improving crop performance in the target environment. The objective of this study was to develop flexible high-throughput root architectural phenotyping platforms for bean and cowpea, which have distinct but comparable root architectures. The bean phenotyping platform was specifically designed to scale from the lab to the field. Initial laboratory studies revealed cowpea does not have basal root whorls so the cowpea phenotypic platform was taken directly to field evaluation. Protocol development passed through several stages including comparisons of lab to field quantification systems and comparing manual and image-based phenotyping tools of field grown roots. Comparing lab-grown bean seedlings and field measurements at pod elongation stage resulted in a R2 of 0.66 for basal root whorl number (BRWN) and 0.92 for basal root number (BRN) between lab and field observations. Visual ratings were found to agree well with manual measurements for 12 root parameters of common bean. Heritability for 51 traits ranged from zero to eighty-three, with greatest heritability for BRWN and least for disease and secondary branching traits. Heritability for cowpea traits ranged from 0.01 to 0.80 to with number of large hypocotyl roots (1.5A) being most heritable, nodule score (NS) and tap root diameter at 5cm (TD5) being moderately heritable and tap root diameter 15cm below the soil level (TD15) being least heritable. Two minutes per root crown were required to evaluate 12 root phene descriptors manually and image analysis required 1h to analyze 5000 images for 39 phenes. Manual and image-based platforms can differentiate field-grown genotypes on the basis of these traits. We suggest an integrated protocol combining visual scoring, manual measurements, and image analysis. The integrated phenotyping platform presented here has utility for identifying and selecting useful root architectural phenotypes for bean and cowpea and potentially extends to other annual legume or dicotyledonous crops.

Basal root whorl number: a modulator of phosphorus acquisition in common bean (Phaseolus vulgaris).

Root architectural phenes enhancing topsoil foraging are important for phosphorus acquisition. In this study, the utility of a novel phene is described, basal root whorl number (BRWN), that has significant effects on topsoil foraging in common bean (Phaseolus vulgaris). Whorls are defined as distinct tiers of basal roots that emerge in a tetrarch fashion along the base of the hypocotyl. Wild and domesticated bean taxa as well as two recombinant inbred line (RIL) populations were screened for BRWN and basal root number (BRN). A set of six RILs contrasting for BRWN was evaluated for performance under low phosphorus availability in the greenhouse and in the field. In the greenhouse, plants were grown in a sand-soil media with low or high phosphorus availability. In the field, plants were grown in an Oxisol in Mozambique under low and moderate phosphorus availability. Wild bean accessions tended to have a BRWN of one or two, whereas cultivated accessions had BRWN reaching four and sometimes five. BRWN and BRN did not vary with phosphorus availability, i.e. BRWN was not a plastic trait in these genotypes. Greater BRWN was beneficial for phosphorus acquisition in low phosphorus soil. Genotypes with three whorls had almost twice the shoot biomass, greater root length and greater leaf area than related genotypes with two whorls. In low phosphorus soil, shoot phosphorus content was strongly correlated with BRWN (R(2) = 0.64 in the greenhouse and R(2) = 0.88 in the field). Genotypes with three whorls had shallower root systems with a greater range of basal root growth angles (from 10 to 45 ° from horizontal) than genotypes with two whorls (angles ranged from 60 to 85 ° from horizontal). The results indicate that BRWN is associated with increased phosphorus acquisition and that this trait may have value for selection of genotypes with better performance in low phosphorus soils.

Root traits of common bean genotypes used in breeding programs for disease resistance

The objective of this work was to assess root traits of 19 common bean genotypes, used in breeding programs for disease resistance. Genotypes DOR 364 and G 19833 were used as deep and shallow basal root checks, respectively. The number of whorls and basal roots were assessed on five-day old seedlings grown in germination paper. Growth pouch studies were conducted to evaluate basal root gravitropism and lateral root length from primary roots, in seven-day old seedlings. The following root gravitropic traits were estimated: basal growth angle, shallow basal root length (localized in the top 2 cm), and relative shallow basal root growth. Number of whorls varied from 1.47 to 3.07, and number of basal roots ranged from 5.67 (genotype TO) to 12.07 (cultivar Jalo MG-65). Cultivars BRS MG Talismã, Carioca, BRS Pioneiro, and Diamante Negro exhibited shallow basal roots, while genotypes Vi-10-2-1, TU, AB 136, and México 54 showed deep basal roots. Cultivar Jalo MG-65 showed more lateral roots from the primary root than the other genotypes. Genotypes used on common bean breeding programs for disease resistance have great variability on basal and primary root traits.

NITROGEN FERTILIZATION REGIME AND LETTUCE ROMAINE TYPES INFLUENCE SEEDLING GROWTH, ROOT ARCHITECTURE AND TRANSPLANT QUALITY

ISHS VII International Symposium on Protected Cultivation in Mild Winter Climates: Production, Pest Management and Global Competition NITROGEN FERTILIZATION REGIME AND LETTUCE ROMAINE TYPES INFLUENCE SEEDLING GROWTH, ROOT ARCHITECTURE AND TRANSPLANT QUALITY

Growth and Architecture of Seedling Roots of Common Bean Genotypes

Common bean (Phaseolus vulgaris L.) is an important food crop in the tropics, where its productivity is often limited by edaphic stress. Root growth and architecture may be associated with genetic adaptation to edaphic stresses. Our objective was to evaluate the effect of genotype, time, and root type on various root growth and architectural parameters in bean seedlings. Seeds of four bean genotypes representing distinct growth habits (erect determinate, erect indeterminate, prostrate indeterminate, and climbing) were grown in containers of Oxisol soil in Cali, Colombia. Plants were harvested at 3‐d intervals and roots divided into basal roots, taproot, and taproot laterals. Length, dry weight, and architecture (topological indices and fractal dimension) of each root class was determined until 14 d after planting. Significant genetic differences were observed in final root length, final root mass, number of basal roots, root growth rate, root elongation rate, number of root meristems, root topology, and root fractal dimension. Some association of shoot habit and root architecture was observed, with the climbing genotype HAB 229 having a more taproot dominated root system, and the prostrate genotype Carioca having a large number of root meristems. The nutrient‐efficient genotype Tostado had a vigorous, highly branched root system with numerous basal roots, while the nutrient‐inefficient genotype Porrillo Sintetico had a smaller, less branched root system. Root type (basal, tap, taproot lateral) and plant age had significant effects on architectural parameters, which may compromise the utility of these parameters as selection criteria.

Seedling Root Morphology and Shoot Growth after Seed Priming or Pregermination of Bell Pepper

Primed, pregerminated, or nontreated seeds of bell pepper (Capsicum annum L.) `Early California Wonder' were grown in controlled conditions for 14 days in glass tubes containing a gel medium. The number of basal roots (one per plant), lateral roots (one per plant), and taproot length (64 mm) did not differ between seed treatments 14 days after seeding. Roots of seedlings from nontreated seeds weighed more than seedlings from primed seeds, and the seedlings had smaller shoot: root ratios than those from pregerminated or primed seeds. Seedlings from pregerminated seeds had heavier and taller shoots than seedlings from nontreated or primed seeds. Taproot length from 1 to 6 days after radicle protrusion increased linearly for all seed treatments. Seedlings from pregerminated seeds initially had longer taproots but had slower linear taproot growth up to 6 days after seeding than seedlings from nontreated or primed seeds.

Pepper (Capsicum annuumL.) root growth and its relation to shoot growth in response to nitrogen

SummaryThe main objective of this work was to investigate shoot and root morphology of pepper (Capsicum annuum L.) (cvs Early Calwonder, Keystone Resistant Giant, Jupiter, Shamrock and Gator Belle) grown in sand culture at three N-levels, 56,84 and 112 mg l−1. Shoot, root, and root components were evaluated 40, 50 and 60 days after seeding. Tap, basal and lateral root accounted for 1%, 40% and 53%, respectively, of the total root dry weight. Shoot: root ratios did not differ between cultivars. Basal root length, basal root number and first-order lateral root number increased with increasing N. Cultivars with either long lateral roots or basal roots had short basal roots or lateral roots respectively, although only small differences were observed in other root and shoot characteristics. In this greenhouse environment, shoot/root ratio was constant. Nitrogen stimulated root and shoot growth, and this effect was significantly different for the root components.

Root Morphological Characteristics of Kidney Beans as Influenced by Within-row Spacing1

Abstract Root morphological characteristics of ‘Redkote’ and ‘Redkloud’ kidney bean plants (Phaseolus vulgaris L.) were measured during 2 growth stages at 5, 10, 15, and 20 cm within-row spacings under field conditions. Significantly higher total root weight, shoot weight, basal root weight, and stem and hypocotyl diameters of individual plants occurred as within-row spacing increased. Uprooting resistance, taproot weight, and taproot diameter increased as within-row spacing increased up to 15 cm followed by a nonsignificant increase at 20 cm. No differences in adventitious root weight or shoot:root ratios occurred among within-row spacing treatments. ‘Redkote’ root parameters were significantly higher than those of‘Redkloud’, with the exception of adventitious root weight and uprooting resistance. Seed yields were highest for 15 cm spacing although not significantly more than at 5 cm spacing. All parameters with the exception of basal root number were significantly lower during anthesis when compared with full pod fill growth stage.

Root Characteristics of Black Beans. II. Morphological Differences Among Genotypes1

Total root biomass of two black bean (Phaseolus vulgaris L.) cultivars, ‘Black Turtle Soup’ (BTS) and ‘Strain 39,’ and four black‐seeded lines (70001, 70002, 70003, and 70004) was partitioned into adventitious, basal, and taproot components at several growth stages under both greenhouse and field conditions. Basal root weights were significantly higher for the four lines in the field and for 70001 and 70002 in the greenhouse than for BTS and Strain 39. Genotypes did not differ for adventitious root weights in both environments. Taproot weights were higher for all the lines compared with BTS; and for 70001, 70003, and 70004 compared with Strain 39 in the field. Genotypes did not differ for taproot weights in the greenhouse.Stem, hypocotyl, and taproot diameters were significantly higher for all the lines than for the two cultivars in the field. Hypocotyl and stem diameters of all lines were higher than for the two cultivars, except for stem diameter of 70002 when compared with BTS in the greenhouse. Taproot diameters of 70001, 70002, and 70004 were significantly higher than for Strain 39 under greenhouse conditions. Basal root diameters (sum of individual basal root diameters) of the four lines were significantly higher than for BTS or Strain 39 in both experiments. Genotypes did^ot differ in the number of basal roots under field conditions.In the field, most root parameters increased up to the seed initiation stage, followed by a significant decrease or no further increase at the pod fill stage. Significant stage ✕ genotype interactions occurred for basal root diameter and hypocotyl diameter in the field and for taproot weight, stem, hypocotyl, and basal root diameters in the greenhouse. The erect plant type of the lines may be attributable to larger basal roots.