scholarly journals 470 Narrow-sense Heritability Estimates for Melon Root Traits

HortScience ◽  
2000 ◽  
Vol 35 (3) ◽  
pp. 475A-475
Author(s):  
Kevin M. Crosby

Improving melon root systems by traditional breeding is one component of the program to develop multiple-stress-resistant melons at the Texas Agricultural Experiment Station, Weslaco. Ten diverse melon lines representing four horticultural groups were intercrossed utilizing a Design II mating scheme. The male parents were: `PI 403994,' `Perlita,' `Doublon,' `Caravelle', and `PI 525106.' The female parents were: `Créme de Menthe,' `Magnum 45,' `BSK,' `PI 124111 × TDI', and `Deltex.' F1 progeny were grown in pasteurized sand in the greenhouse using a randomized complete-block design with four reps. After 4 weeks, root systems from all plants were carefully washed to remove the sand. Each root system was then placed onto a glass, plated, and scanned into the computer software Rhizo Pro 3.8 (Regent Instruments, Quebec). This software calculated root lengths of various diameter classes, root area, and root tip number. All data was input into Agrobase software for calculation of genetic variances based on Design II analysis. Significant differences of contributions by male parents to progeny variation were few. Only length of roots with 1.0- to 1.5-mm-diameter and vine length were significantly different. Differences in contributions by female parents to all traits except root tip number were highly significant. No significant interaction effects were observed for any trait. Narrow-sense heritability estimates were moderate to high for all traits. The range was from 0.56 for root tip number by males to 0.81 for both length of 0.5- to 1.0-mm-diameter roots and vine length for females. Estimates for total root length (0.76) and root surface area (0.77) were high. The lack of male by female interaction suggests very low dominance genetic variation and contributed to high heritability estimates, which represent predominantly additive gene action. Additive genetic variation allows more-efficient progress by selection, making the potential for root system improvement favorable.

Agronomy ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1845
Author(s):  
Santosh Nayak ◽  
Hem Bhandari ◽  
Carl Sams ◽  
Virginia Sykes ◽  
Haileab Hilafu ◽  
...  

Switchgrass (Panicum virgatum L.) is a warm-season, perennial grass valued as a promising candidate species for bioenergy feedstock production. Biomass yield is the most important trait for any bioenergy feedstock. This study was focused on understanding the genetics underlying biomass yield and feedstock quality traits in a “Kanlow” population. The objectives of this study were to (i) assess genetic variation (ii) estimate the narrow sense heritability, and (iii) predict genetic gain per cycle of selection for biomass yield and the components of lignocelluloses. Fifty-four Kanlow half-sib (KHS) families along with Kanlow check were planted in a randomized complete block design with three replications at two locations in Tennessee: Knoxville and Crossville. The data were recorded for two consecutive years: 2013 and 2014. The result showed a significant genetic variation for biomass yield (p < 0.05), hemicellulose concentration (p < 0.05), and lignin concentration (p < 0.01). The narrow sense heritability estimates for biomass yield was very low (0.10), indicating a possible challenge to improve this trait. A genetic gain of 16.5% is predicted for biomass yield in each cycle of selection by recombining parental clones of 10% of superior progenies.


2018 ◽  
Vol 28 (5) ◽  
pp. 629-636 ◽  
Author(s):  
Matthew B. Bertucci ◽  
David H. Suchoff ◽  
Katherine M. Jennings ◽  
David W. Monks ◽  
Christopher C. Gunter ◽  
...  

Grafting of watermelon (Citrullus lanatus) is an established production practice that provides resistance to soilborne diseases or tolerance to abiotic stresses. Watermelon may be grafted on several cucurbit species (interspecific grafting); however, little research exists to describe root systems of these diverse rootstocks. A greenhouse study was conducted to compare root system morphology of nine commercially available cucurbit rootstocks, representing four species: pumpkin (Cucurbita maxima), squash (Cucurbita pepo), bottle gourd (Lagenaria siceraria), and an interspecific hybrid squash (C. maxima × C. moschata). Rootstocks were grafted with a triploid watermelon scion (‘Exclamation’), and root systems were compared with nongrafted (NG) and self-grafted (SG) ‘Exclamation’. Plants were harvested destructively at 1, 2, and 3 weeks after transplant (WAT), and data were collected on scion dry weight, total root length (TRL), average root diameter, root surface area, root:shoot dry-weight ratio, root diameter class proportions, and specific root length. For all response variables, the main effect of rootstock and rootstock species was significant (P < 0.05). The main effect of harvest was significant (P < 0.05) for all response variables, with the exception of TRL proportion in diameter class 2. ‘Ferro’ rootstock produced the largest TRL and root surface area, with observed values 122% and 120% greater than the smallest root system (‘Exclamation’ SG), respectively. Among rootstock species, pumpkin produced the largest TRL and root surface area, with observed values 100% and 82% greater than those of watermelon, respectively. These results demonstrate that substantial differences exist during the initial 3 WAT in root system morphology of rootstocks and rootstock species available for watermelon grafting and that morphologic differences of root systems can be characterized using image analysis.


Author(s):  
Alireza Haghighi Hasanalideh ◽  
Mehrzad Allahgholipour ◽  
Ezatollah Farshadfar

This study was undertaken to assess the combining ability of 6 rice varieties, for viscosity parameters and determining gene action controlling Rapid Visco Analyser (RVA) characters. F2 progenies derived from a 6×6 half diallel mating design with their parents were grown in a randomized complete block design with three replications at the research farm of Rice Research Institute of Iran (RRII) in 2015. The diallel analysis by Griffing`s method indicated the involvement of additive and non-additive gene actions controlling RVA traits. For traits PV and FV RI18447-2 and IR50 were the best combiners for increasing and decreasing, respectively. Deylamani and IR50 were the best combiners for increasing and decreasing BV, respectively. Beside, due to more portion of non-additive gene action in controlling trait SV, The Gilaneh × RI18430-46, and Deylamani × RI18430-46 crosses were the best for increasing and decreasing SV, respectively. The high estimates of broad sense heritability and narrow sense heritability for BV and FV, indicated the importance of additive effects in expression of these traits. Therefore, selection base breeding methods will be useful to improve these traits and selection in the early generations could be done to fix the favourable genes. Low estimate of narrow sense heritability for SV revealed that non-additive gene effects play important role in controlling setback viscosity. So, hybrid base breeding methods will be useful to improve this trait.


Plant Methods ◽  
2019 ◽  
Vol 15 (1) ◽  
Author(s):  
Yu Liu ◽  
Ji Qian ◽  
Xin Yang ◽  
Bao Di ◽  
Juan Zhou

Abstract Background Traditional measurements of apple seedling roots often rely on manual measurements and existing root scanners on the market. Manual measurement requires a lot of labor and time, and subjective reasons may cause the uncertainty of data; root scanners have limited scanning size and expensive. In case of fruit roots, coverage and occlusion issues will occur, resulting in inaccurate results, but our research solved this problem. Results The background plate was selected according to the color of the seedling roots; the image of the roots of the collected apple seedlings was preprocessed with Vision Development Module by combining image and Labview. The root surface area, average root diameter, root length and root volume of apple seedlings were measured by combining root characteristic parameters algorithm. In order to verify the effectiveness of the proposed method, a set of measurement system for root morphology of apple seedlings was designed, and the measurement result was compared with the Canadian root system WinRHIZO 2016 (Canada). With application of SPSS v22.0 analysis, the significance P > 0.01 indicated that the difference was not significant. The relative error of surface area was less than 0.5%. The relative error of the average diameter and length of the root system was less than 0.1%, and the relative error of the root volume was less than 0.2%. Conclusions It not only proved that the root surface area, average root diameter, root length and root volume of apple seedlings could be accurately measured by the method described herein, which was handy in operation, but also reduced the cost by 80–90% compared with the conventional scanner.


2017 ◽  
Vol 2 (1) ◽  
Author(s):  
Manuel A. Gastelo Benavides ◽  
Luis Diaz ◽  
Gabriela Burgos ◽  
Thomas Zum Felde ◽  
Merideth Bonierbale

AbstractHigh temperatures affect potato production in the tropics, putting tuber yield and quality at risk and leading to increased glycoalkaloid concentration the cause of the bitter taste in potatoes and a cause for concern for human health. The International Potato Center (CIP), has developed new heat tolerant clones which are heat tolerant and also resistant to late blight. These clones offer an opportunity to evaluate yield and glycoalkaloid levels after growth under high temperature environments. We evaluated four sets of 16 full-sib families and 20 clones for tuber yield and glycoalkaloid content in order to estimate narrow-sense and broad-sense heritability respectively. We used a randomized complete block design replicated in three locations in Peru; San Ramon, La Molina and Majes At harvest, the number and weight of marketable and nonmarketable tubers were recorded. We analyzed samples of tubers from each clone for glycoalkaloid content using spectrophotometry. Narrow-sense heritability for tuber yield, tuber number and average tuber weight were 0.41, 0.50 and 0.83, respectively, indicating that further gains in breeding for heat tolerance will be possible. Broadsense heritability for glycoalkaloid content was 0.63 and correlation with tuber yield was weak, r=0.33 and R²=0.11 (P<0.01). High heritability and weak correlation will allow us to select clones with high tuber yield and low glycoalkaloid content, to serve as candidate varieties and parents in breeding programs.


2015 ◽  
Author(s):  
F. Muñoz ◽  
B. Marçais ◽  
J. Dufour ◽  
A. Dowkiw

AbstractSince the early 1990s, ash dieback due to the invasive ascomycete Hymenoscyphus fraxineus is threatening Fraxinus excelsior in most of its natural range. Previous studies reported significant levels of genetic variability for susceptibility in F. excelsior either in field or inoculation experiments. The present study was based on a field experiment planted in 1995, fifteen years before onset of the disease. Crown and collar status were monitored on 788 trees from 23 open-pollinated progenies originating from 3 French provenances. Susceptibility was modeled using a Bayesian approach where spatio-temporal effects were explicitly taken into account. Moderate narrow-sense heritability was found for Crown Dieback (CD, h2=0.42). This study is first to show that Collar Lesions are also heritable (h2=0.49 for prevalence and h2=0.42 for severity) and that there is significant genetic correlation (r=0.40) between the severities of both symptoms. There was no evidence for differences between Provenances. Family effects were detected, but computing Individual Breeding Values (IBV) showed that most of the genetic variation lies within families. In agreement with previous reports, early flushing correlates with better crown status. Consequences of these results in terms of management and breeding are discussed.


2020 ◽  
Vol 48 (4) ◽  
pp. 2263-2278
Author(s):  
Hang ZHOU ◽  
Dianfeng ZHENG ◽  
Naijie Feng

Spatial and temporal distribution of roots of mung bean and soybean originated from different geographical backgrounds is an important scientific issue. The aim of this study was to research the spatial and temporal distribution of roots system of soybean cultivar ‘Hefeng55’ and mung bean cultivar ‘Jilv7’ which can elucidate differences between soybean roots and mung bean roots in the key spatial and temporal locations. The roots at V6, R2, R4, R5, R6, and R7 stages were collected to acquire data of root length, root surface area, root volume and root dry weight. 49.8%, 11.7%, 13.2%, 14.7% and 10.6% of soybean roots and 57.8%, 10.7%, 11.2%, 11.9% and 8.4% of mung bean roots were in 0-5, 5-10, 10-15, 15-20 and 20-25 cm horizontal soil layers, respectively; 79.2%, 11.5%, 4.3%, 1.8%, 1.1%, 1.0% and 1.1% of soybean roots and 70.0%, 12.3%, 8.0%, 3.0%, 1.6%, 1.7% and 3.4% of mung bean roots were in 0-20, 20-40, 40-60, 60-80, 80-100, 100-120 and 120-140 cm vertical soil layers, respectively. Compared with mung bean, soybean had a much larger root system during development. In horizontal direction, soybean root tended to be more laterally developed, but the distribution of mung bean root was more uniform in vertical direction. With a greater root surface area to weight ratio (AWR), mung bean had a finer root system than soybean. These findings can help to clarify the four-dimensional spatial and temporal distribution characteristics of legumes and may provide reference for production practice of soybean and mung bean in the future.


2021 ◽  
Vol 3 (3) ◽  
pp. 10-17
Author(s):  
A. Sheidu ◽  
T. M. Igyuve ◽  
A. E. Ochigbo

The study was conducted at the Teaching and Research Farms, Federal University of Agriculture, Makurdi, Nigeria. Five Cowpea genotypes (FUAMPEA-1, IT99K-573-1-1, SAMPEA-16, SAMPEA-8, BIU LOCAL) were crossed and advanced to F1, F2, BC1 and BC2 populations using bi-parental mating design. The six generations were evaluated in a Randomized Complete Block Design with three replications. Significant test of the mean performances among the entries showed significant differences among the generations for the characters studied. Wide ranges of narrow sense heritability (18 to 79%), broad sense heritability (21 to 92%) and genetic advance (5.7 to 24.1%) were obtained for characters studied. Broad and narrow sense heritability as well as genetic advance was moderate to high for most of the characters studied such as days to 50% flowering, plant height, days to pod maturity, number of seeds per pod, number of pods per plant, hundred seed weight, root length and grain yield for the three sets of cowpea crosses. The results also revealed the possibility of exploitation for grain yield and drought tolerance in the crosses studied.


Plant Methods ◽  
2021 ◽  
Vol 17 (1) ◽  
Author(s):  
Takuya Koyama ◽  
Shun Murakami ◽  
Toshihiko Karasawa ◽  
Masato Ejiri ◽  
Katsuhiro Shiono

Abstract Background Detailed datasets containing root system and its architecture in soil are required to improve understanding of resource capture by roots. However, most of the root study methods have paid little attention to make and preserve whole root specimens. This study introduces root system sampling equipment that makes the entire root specimen with minimum impairment and without displacement of the spatial arrangement of the root system in root boxes. The objectives are to assess: whether the equipment can rapidly sample the entire root system; whether root surface area is measurable from a scanned digital image of the root specimen; and whether staining of the entire root specimens would provide multidimensional visual information on the interaction between soil and physiological function of root system architecture (RSA). For validation, we examined the root response of two soybean cultivars to arbuscular mycorrhizal (AM) inoculation and the effect of waterlogging stress on the physiological activity of buckwheat RSA. Results The root boxes allowed soybean and buckwheat plants to grow uniformly across the replications. Both species showed significant differences between cultivars and/or among treatments in shoot and root traits. The equipment enabled to sample the whole-root specimens of soybean and buckwheat, where the tips of the fine roots were alive (diameter < 0.2 mm). Also, the whole root specimens of soybean were made in about 7 min. The root surface area calculated from the scanned soybean specimens showed a significant correlation with that calculated from the roots spread out in water (a common method). Staining of the soybean root specimens enabled us to observe the localized root proliferation induced by AM colonization. Moreover, staining of the buckwheat root specimens made it possible to examine the respiratory activity of each root at different depths. Conclusions The present method realized: fast and accurate production of the whole root specimen and precise calculation of the specimens’ root surface area. Moreover, staining of the root specimens enabled analyzing the interaction between soil and physiological function of RSA. The evaluation of root traits, using our methods, will contribute to developing agronomic management and breeding program for sustainable food production.


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