Pod Position Research Articles

Risk analysis and cacao pod survivorship curves to improve yield forecasting methods

Cocoa attainable yields are affected by a complex of pests and diseases in a particular agro-environment. Estimation of yield loss is critical for agronomic and economic decision-making at the farm level. For over 15 months, we monitored 1100 pods from six cocoa clones (PMCT-58, CC-137, CATIE-R1 CATIE-R4, ICS-95, and CCN-51) to assess the incidence of pests and diseases and to elucidate their survival behavior. Cocoa clones grow in a 12-year timber-based cocoa agroforestry plot (1330 cocoa plants ha-1, 100 shade trees ha-1, and 65% shade cover), in La Montaña, Turrialba, Costa Rica. Between 6-12 trees and 120-140 pods per clone of four size classes (very small – 2.5-7 cm, small – 7.1-14 cm, medium – 14.1-21 cm, and large – ≥21 cm) were tagged and measured fortnightly. Pods were selected at two vertical strata along the tree trunk (below and above 1.5 m) and grouped into three generations (rainy, transition, and dry). Competitive risk and survival analysis were performed per clone, generation, pod size class, and pod position along the tree trunk. Overall, pods reached maturity at the age of 155-165 days and were exposed to several hazards that disrupted their development. The Cox model that better described the cumulative risk during pod development included two covariables with substantial explicative power, generation, and clones. Regardless of clone and pod generation, a combination of diseases/pests accounted for about 45% to 65% of yield losses. The Kaplan-Meier survival analysis showed that pod survival was similar between generations but differed among clones within generations. Pods from CATIE-R1, CATIE-R4 and CC-137 clones showed greater survival rates than those of ICS-95, CCN-51 and PMCT-58 clones. The position of the pod along the tree trunk did not influence pod survival rates. We combined pod counting and pod survival rates calculated in this study and contrasted our yield estimations against a widely used prediction method proposed by a certification body. Overall, yield estimated using the UTZ method applied to 90-day-old pods of CATIE-R1 clone consistently overestimated yield predictions in the range of 27-45%. We proposed the combination of pod counting and pod index with a set of clone-specific discount factors; the survival rates, to reliably forecast on-farm cacao yields over time.

Effect of seed size and pod position of clove (Syzigium aromaticum) to seed viability

Cloves are commonly propagated generatively using true seed. One of the factors causing the lack of qualified clove seeds is farmers^ low awareness of using high-quality seeds. Farmers usually do not produce seeds- in particular, they obtain seeds from their trees without exclusively separating trees for making seeds and flowers. The seeds are randomly harvested from all the flowers without considering the pod position and size. This study aimed to evaluate the effect of pod position and size on clove seed viability. The research was conducted at the Glass House of Indonesian Spices and Medicinal Crops Research Institute, Indonesia, from August to December 2018. The study was arranged in a completely randomized design with two factors. The first factor was the seed size: large (≥ 0.9 g) and small (< 0.9 g). The second factor was pod position : (a) the pods exposed to the morning sun, (b) the pods exposed to the afternoon sun, and (c) the pods’ unexposed sun (hidden). The pods originated from selected mother trees from Kayu Aro, West Sumatra. The results showed that seed size ≥ 0.9 g and pods exposed to the morning sun had higher viability, as indicated by the high seed growth rate, vigor, and better plant growth than other treatments.

Technical note: Multi-MATE, a high-throughput platform for automated image-guidedsmall-animal irradiation.

Small animal irradiation is essential to study the radiation response of new interventions before or parallel to human therapy. Image-guided radiotherapy (IGRT) and intensity-modulated radiotherapy (IMRT) are recently adopted in small animal irradiation to more closely mimic human treatments. However, sophisticated techniques require exceedingly high time, resources, and expertize that are often impractical. We propose a high throughput and high precision platform named Multiple Mouse Automated Treatment Environment (Multi-MATE) to streamline image-guided small animal irradiation. Multi-MATE consists of six parallel and hexagonally arranged channels, each equipped with a transfer railing, a 3D-printed immobilization pod, and an electromagnetic control unit, computer-controlled via an Arduino interface. The mouse immobilization pods are transferred along the railings between the home position outside the radiation field and the imaging/irradiation position at the irradiator isocenter. All six immobilization pods are transferred to the isocenter in the proposed workflow for parallel CBCT scans and treatment planning. The immobilization pods are then sequentially transported to the imaging/therapy position for dose delivery. The positioning reproducibility of Multi-MATE are evaluated using CBCT and radiochromic films. While parallelizing and automating the image-guided small animal radiation delivery, Multi-MATE achieved the average pod position reproducibility of 0.17 ± 0.04 mm in the superior-inferior direction, 0.20 ± 0.04 mm in the left-right direction, and 0.12 ± 0.02mm in the anterior-posterior direction in repeated CBCT tests. Additionally, in image-guided dose delivery tasks, Multi-MATE demonstrated the positioning reproducibility of 0.17 ± 0.06 mm in the superior-inferior direction, 0.19 ± 0.06 mm in the left-right direction. We designed, fabricated, and tested a novel automated irradiation platform, Multi-MATE to accelerate and automate image-guided small animal irradiation. The automated platform minimizes human operation and achieves high setup reproducibility and image-guided dose delivery accuracy. Multi-MATE thus removes a major barrier to implementing high-precision preclinical radiation research.

Effect of Sowing Date and Environment on Phenology, Growth and Yield of Lentil (Lens culinaris Medikus.) Genotypes.

Lentil, an important pulse crop in Australia, is sown soon after the onset of autumn rains and grows mainly under rainfed conditions. This study examined lentil phenological development, growth and grain yield under different sowing dates and environments in New South Wales (NSW). Eight lentil varieties were phenotyped over two years and four sowing times in southern NSW (Leeton, Wagga Wagga and Yanco (one year)) and central western NSW (Trangie). Time of sowing affected important agronomic traits, with a delay in sowing decreasing time to flowering and podding, biomass accumulation, plant height and position of bottom pod. Sowing earlier or later than optimum decreased grain yield. Yield was mainly determined by the number of pods and seeds per plant, with minimal impact from seed weight. Overall, yields were higher in favorable environments such Leeton experiment which received more water compared to the other sites which received less water. Averaged across sowing dates, the slower maturing PBA Greenfield was lower yielding whilst fast maturing varieties such as PBA Bolt and PBA Blitz yielded higher. PBA Jumbo2 is less sensitive to environmental interaction and thus broadly adapted to the diverse environments. Optimum sowing time was identified as the end of April to mid-May.

The Technical Parameters of Seaweed Biostimulant Spray Application as a Factor in the Economic Viability of Soybean Production

Application of biostimulant in the form of a spraying requires appropriate selection of technical parameters. One of the key factors in ensuring that the liquid is sprayed correctly is the choice of suitable spray nozzles. This study investigated selected technical parameters of seaweed biostimulant spray applications as a factor for plant biometrics, crop quality and yield, and the economic viability of production. This objective was achieved by conducting a two-year field experiment involving spraying soybean plants with a biostimulant containing seaweed extract. The spraying was carried out with two types of nozzles (standard and air-injector), for which the droplet size and the degree of plant coverage were tested at 4.0 MPa. The surface tension of the spray liquid and the area and volume of the droplets were tested. The height of soybean plants, the height and the position of the first pod, the number of pods, seed yield, and the weight of 1000 seeds were measured. The physical properties of the liquid sprayed on the plants and the type of nozzles used were factors affecting the height of the first pods, plant height, and protein content. The application of biostimulants using standard nozzles is more economically advantageous compared to nozzles with an air-injector.

Morphological characterization and new variation in compound leaf of mungbean (Vigna radiata L. Wilczek) genotypes

The present investigation was executed under field conditions that favour normal growth and expression for all descriptors. A collection of 40 mungbean genotypes were characterised for 21 agro-morphological traits during the summer 2021 and 2022. The experimental material was &nbsp;evaluated in three replications in RCBD and observations were recorded as per DUS guidelines. The&nbsp; phenotypic assessment showed polymorphism for &nbsp;the characters such as hypocotyl anthocyanin coloration, stem colour, leaf shape, leaf colour, leaf vein colour, petiole colour, flower petal colour, pod position, pod colour, pod curvature, seed colour, seed size etc. Some special character including yellow seed colour of local germplasm ‘yellow-mung’ diversified the crop. Furthermore, an increased number of leaflet viz. quadrifoliate and pentafoliate compound leaf variations were also observed rather than the normal trifoliate compound leaf of mungbean. The standard descriptors can be used as a marker to characterize the crop species for utilization of germplasm and conservation programmes. Keywords: characterization, compound leaf, DUS, greengram, polymorphism

Characterization of the green gram (Vigna radiata L.) genotypes through both morphological and biochemical parameters

Eight genotypes of greengram were collected in the present investigation from AICRP on MULLaRP, Bidhan Chandra Krishi Viswavidyalaya (BCKV) and they were characterized with ten quantitative, nineteen qualitative and two biochemical parameters as per the NBPGR descriptor. Grouping based on DUS descriptors indicate the existence of genetic diversity within the genotypes. These eight genotypes were evaluated and characterized for 31 DUS descriptors. However, 21 characters out of 31 characters of DUS descriptors differed significantly indicating a large and exploitable amount of genetic variability for the individual elite improved line profile development for identification and protection. The elite lines are similar for the important plant traits like semi erect and determinate growth habit but the development of erect types is the need of hour and indicates the incorporation of new germplasm for the improvement of this trait in the present material. Genotypes could be easily identified through some unique characters: SML-1822 could be identified amongst genotypes studied here in through its semi-erect growth habit, green stem colour with purple shade, dark green leaf colour, light yellow flower colour and bearing pods below canopy; identification of IPM-512-1 and TMB-37 could be made through seeds with drum shape and dull seed luster respectively; and Pusa Vishal through its leaves with dark green colour along with intermediate pod position and larger seed size. Samrat is having highest amount of protein as well as carbohydrate content among these genotypes. Thus, the DUS descriptor data generated with unique profiles of the elite improved lines can be used for the registration with PPV &amp; FRA and seed purity testing.

PHYSICAL QUALITY AND PRODUCTIVITY OF COCOA BEAN (Theobroma cacao L.) BASED ON CANOPY POSITION AND PLANT AGE

The research aimed to study the cocoa bean quality and productivity based on their position on canopy and different plant ages. This has been conducted at cocoa farming area at Wonggeduku Subdistrict, Konawe Regency, Southeast Sulawesi Province. These treatments were arranged based on the nested design in which the pod position on the canopy i.e. on main stem, primary and secondary branches, and nested to the plant ages i.e. 8,10, 12, and 14 years old were used. The observed variable were pod length, pod diameter, seed weight, seed number, and dry production per pod. The data gathered were analysed by analysis of variance and the difference between treatments were justified by Duncan’s Multiple Range Test at 95% significant level. To study the relationship between plant ages and pod position on canopy, the regression analysis was applied. Research result showed that there were interaction effect on pod position and ages on all variable observed. The best treatment on the main stem and primary branch at eight year age of the plant was on the length, diameter and weight of pods, seed number, and dry seed production per pod. KEY WORDS: Cocoa pod, plant age, pod position, production, quality

Physiological quality of conventional soybean cultivars of seeds as a function of pod position in plant canopy

Soybean cultivars have different growth habits, and the cultivation of those of indeterminate habit has increased significantly in Brazil. Thus, the aim of this study was to evaluate the physiological quality of soybean seeds produced in two harvests, from cultivars with different growth habits and ripening cycles, harvested in different canopy thirds of the plant in the canopy. The seeds were produced in Ipameri, Goiás –Brazil, in two crop harvests, 2014/15 and 2015/16. A completely randomized design was used in a 4x3 factorial scheme with four replications. The treatments consisted of four soybean cultivars with different growth habits and ripening cycles (BRS 6780, BRS 6980, BRS 7980 and BRS 8381), harvested in three positions of the plant canopy (upper, middle and lower). Germination, first count, accelerated aging and electrical conductivity tests were performed. It was observed that the physiological quality of genetic materials studied was influenced by the variable environmental conditions. Soybean cultivars the early cycles produced seeds of superior physiological quality, regardless of plant growth habit. Seeds of soybean cultivars of indeterminate and determined growth habits and earlier cycle, harvested from the upper and middle thirds of the plant, are of better quality. Finally, cultivars with semi-determined and determined habits and late cycles will produce lower quality batches of seeds, regardless of which third of the plant they were harvested.

Impact of heat stress on pod‐based yield components in field pea (Pisum sativumL.)

AbstractElevated temperatures associated with climate change result in crops being exposed to frequent spells of heat stress. Heat stress results in reduced yield in field pea (Pisum sativumL.); it is therefore important to identify cultivars with improved pod and seed retention under heat to mitigate this loss. Objectives were to investigate the effect of heat stress on phenology, yield and pod‐based yield components. Sixteen pea cultivars were evaluated at normal and late (hot) seeding dates in the field in Arizona 2012 and in growth chambers with two temperature regimes (24/18°C and 35/18°C day/night temperature for 7 days) during reproductive development. We measured variation in the pattern of pod retention at four‐node positions on plants, seed retention by ovule position (stylar, medial and basal) within pods and screened cultivars for pod retention, seed retention and yield. Heat stress reduced seed yield by accelerating the crop lifecycle and reducing pod number and seed size. Heat stress had the most damaging effect on younger reproductive growth (flowers and pods developed later), resulting in ovary abortion from developing flowers. Heat also accelerated seed abortion in all ovule positions within pods. Two high‐yielding cultivars under control temperature, “Naparnyk” and “CDC Meadow”, maintained high yield in heat, and “MFR043” had the lowest yield. Cultivars “40‐10” and “Naparnyk” retained the most ovules and seeds per pod, and “MFR043” aborted seeds when exposed to heat. In half of the cultivars, ovules at the basal peduncle end of pods were likely to abort while ovules at the medial and stylar end positions developed into seeds. For seven of the field cultivars, ovules at the medial pod position also produced mature seeds. Cultivars “40‐10”, “Naparnyk” and “CDC Meadow” had greater pod and ovule retention or maintained high yield under heat stress, and were identified as heat‐tolerant cultivars. Our results allow for a better understanding of pod‐based yield components in field pea under heat stress and developing heat‐tolerant cultivars.

The Effect of Seed Position in Pod on The Seed Viability of Cowpea (Vigna unguiculata)

In Indonesia, cowpea (Vigna unguiculata L. Walp) is widely cultivated in the dry climate area. Famers used the seeds from previous plants or traditional markets. The aims of the study were to determine the effect of seed position in the pods on seed viability and to study the seed and seedling characteristics regarding the genetic variation and seed position. The cowpea used in this study was from 18 Indonesian local varieties. Twenty-five matured pods were randomly detached from each variety. Each pod was divided into three parts, i.e. the lower third (base), the middle third, and the upper third (tip). The seeds of each part were germinated using sand media to evaluate their viability. Each local variety has different response to the percentage of seed viability in each seed position in the pod. The highest abnormal germination occurred in the seed from lower part of the pod, followed by seed in the middle of the pod and the tip of the pod. The variation of seed viability in pods was more determined by genetic differences in local varieties. The average seed viability from three parts of the pods was highest for seeds originated from local varieties of Lumajang and Sampang. Therefore, it is recommended that the seeds of both local varieties can be mixed to be used for optimum cowpea cultivation.

Defining features of age-specific fertility and seed quality in senescing indeterminate annuals.

A trade-off between fertility and offspring viability underpins plantreproductive response to sub-optimal environmental conditions. Senescence involves internal resource limitation, and it is a sub-optimal body condition. We tested if senescence affects age-specific fertility and seed viability (quality) in indeterminate annuals. Fertility in individual pods on the monopodial indeterminate inflorescence of Arabidopsis thaliana and its big-seeded relative Brassica nigra was quantified. The reproductive phase was divided into three phases: (1) early-senescence (initial flowers) (2) mid-senescence and (3) late-senescence (wilting leaves). Seed-viability probability as a function of pod position on the inflorescence (a proxy for parent's age) and seed position within pod was verified by germination tests in Brassica and then analysed using a binomial logistic regression model. Age-specific fertility increased gradually, peaked, and then declined significantly during senescence in Arabidopsis and Brassica. Acropetal size distribution of rosette leaves was similar to that of pods (age-specific fertility) in Arabidopsis. Seeds positioned closest to stigma tended to be heavier and more viable than others in highly fertile pods, characteristic of mid-senescence phase in Brassica. Pod position (parent's age) was a significant predictor of seed-viability probability or seed quality, which improved in old and senescing Brassica. High viability probability of seeds produced in low-fertility pods during late-senescence phase suggests weakening of maternal control over seed-size optimization (bigger, fewer, and better seeds) in internally resource-depleted older parent plants. Proximity to stigma can increase seed quality. The unexpected increase in fertility and seed viability during early-senescence phase is likely due to highly conserved developmental constraints on leaf and pod phenotype. Indeterminate annuals can shed light on fertility, offspring quality and senescence relationships in all plants that reproduce sexually and indeterminately.

Pseudosatellite Dynamic Positioning of UAV Pod Based on an Improved SR-UKF Algorithm

In view of the practical engineering problem of dynamic positioning of rotor UAV pod and the strong nonlinear problem in dynamic operation of UAV, a real-time estimation of the dynamic position of the rotor UAV pod is proposed by using the SR-UKF algorithm. This algorithm uses the nonlinear propagation of UT transform to generate the point set to maintain the mean and covariance information and thus achieves higher precision. Moreover, it uses the square root of covariance instead of covariance to participate in the recursive operation, thus improving the numerical stability of the filter and reducing the amount of computation. In this work, a pseudosatellite positioning platform was constructed in a field site in Nanjing. Based on evaluation of the space geometry of pseudosatellite base station, the accuracy of several nonlinear filtering algorithms was analyzed and evaluated using GPS RTK positioning results. It was found that the SR-UKF algorithm was the most accurate and efficient algorithm. It can meet the requirements of dynamic positioning of the rotor-wing UAV pod. The experiment results of this algorithm provide a more efficient positioning algorithm and implementation means for the actual engineering of UAV pod positioning using pseudosatellite system, which has high application value.

The effect of water shortage on pea (Pisum sativum L.) productivity in relation to the pod position on the stem

The literature contains few studies on the effect of temporary soil drought on the development and productivity of pea (&lt;em&gt;Pisum sativum&lt;/em&gt; L.) pods in relation to their position in the fruiting part of the stem. The aim of this study was to evaluate pod productivity of various pea cultivars in relation to varied weather conditions. Differences in precipitation during two growing seasons resulted in a decrease in yield of 0.62 t ha&lt;sup&gt;−1&lt;/sup&gt; in a dry year in comparison to a year with better water availability. &lt;em&gt;Pisum sativum&lt;/em&gt; ‘Tarchalska’ proved to be the most stable in terms of the number of pods produced, whilst ‘Prophet’ was the least. Weather conditions and cultivars were the determinants of pod production. Pea pods were distinguished by their position on the productive node. Larger and more productive pods were found on the lowest four productive nodes (which had a longer period of nutrient accumulation) resulting in higher seed mass. Productivity increased in the year with favorable weather conditions, as more of the upper nodes were reproductive. The first four nodes produced 45–91% of the yield. The number of seeds in the first three nodes was significantly cultivar-dependent, whereas the number of seeds in pods at all nodes was determined by weather conditions. Significantly more seeds were formed from each node in the wetter year. &lt;em&gt;Pisum sativum&lt;/em&gt; ‘Audit’ was not sensitive to weather conditions, producing the same yield in the both years of the study.

Influence of media context on humorous advertising effectiveness

PurposeThe purpose of this paper is to study the impact of three dimensions of media context – program type, break type, and pod position – on two types of humorous advertisements: incongruity resolution (IR) and arousal safety (AS). The study aims to demonstrate that different humor types are evaluated differently under similar media context elements and a particular humorous advertisement can be evaluated differently under different elements of media context.Design/methodology/approachThe hypotheses were tested through two experiments which were planned and conducted as “between-subjects” design. The analysis of collected data were done through ANOVA using IBM SPSS 22.FindingsThe results indicated that the adverse impact of negative mood (vs positive mood) was greater on IR advertisements as compared to AS advertisements. Similarly, the negative impact of an abrupt break (vs smooth break) was greater on IR advertisements. However, both humor types were effective when placed in positive mood programs and smooth breaks.Practical implicationsThe findings suggest that campaign and media planners need to consider the media context as well as humor types to get better return on their adspend. Results of this study can also be applicable for online medium.Originality/valueThis is the first study to test the impact of three dimensions of media context on two types of humorous advertisements.

Seed Yield and Quality of Okra (Abelmoschus esculentus (L.) Moench) as Influenced by Sowing Dates, Harvest Date and Pod Position

Seed production and quality of okra were obviously influenced by sowing date, harvest date and pod position on the mother plant. The aim of the present study was to determine the effect of sowing dates (1st March, 1st April and 1st May), harvest dates (30 , 40 and 50 days after anthesis (DAA)) and pod position on plant (lower, middle and upper) on seed yield and quality of okra (Balady cv.). Two field experiments were carried out during the summer seasons of 2013 and 2014 at Shandaweel Agriculture Research Station, ARC, Sohag Governorate, Egypt. The obtained results indicated that, sowing okra plants on 1st April increased all studied characters compared to other sowing dates of 1st March, or 1st May. Harvesting pods at 40 or 50 days after anthesis gave the maximum germination percentage comparing to early harvest at 30 days after anthesis. Pods at lower or middle positions on the okra plant exhibited the best values in seed yield in terms of seeds number/pod, seeds weight/ pod, 100 seed weight and quality in terms of germination percentage, root and shoot length of seedlings. All possible combinations had significant effect on pod diameter, seed index, germination percentage and shoot in both seasons. The highest values were obtained from pods of plants sown on in 1st April and their pods harvesed from lower or middele postions after 40 days after anthesis.It could be recommended from the previous results the highest seed yield and quality was obtained in okra under the condition of this experiment and similar conditions, following planting okra on 1st April and harvest till 8 th pod after 40 days from anthesis.

Genetic diversity analysis in green gram based on morphological traits

Twenty three advanced breeding lines of green gram, developed at different centres under the All-India Coordinated Research Project on MULLARP, were evaluated by growing them during summer to characterize the genotypes and to assess the magnitude of genetic diversity in the genotypes. Genetic dissimilarities as revealed by Euclidean distances ranged from 2.891 to 10.494. Maximum distance was observed between ML 1354 and MH 721. Based on Euclidean distances four clusters were formed. Cluster II was the largest, and was further divided into two sub-clusters, IIA and IIB, comprising of four and nine genotypes, respectively. Genotypes MH 709 and KM 2272 belonging to cluster I were closely placed as they shared most of the characters. But they could be distinguished with the help of characters like days to 50% flowering, position of pods in the plant and growth habit. Similarly, GM 04-02 and NM 1 in sub-cluster IIA were closely grouped, and they could be distinguished based on the characters leaf size and pod length. Similarly other closely grouped genotypes were also distinguishable on the basis of some characters. It was observed from the average Euclidean distances that ML 1354, SG 1, MH 721, SG 63-14 and MH 709 were divergent genotypes. These genotypes were potential parents in green gram breeding programme.

New approach to determine biological and environmental factors influencing mass of a single pea (Pisum sativum L.) seed in Silesia region in Poland using a CART model

There are many factors that influence the mass of a single pea seed. Because peas are an important edible legume crop of high biological value, we aimed at assessing the determinants of a single pea-seed mass based on thirteen predictors, grouped as: morphological, weather and Rhizobium vaccines. In a three-year field experiment, the biological and habitat characteristics of the yielding of two edible peas, i.e., semi-leafless cv. ‘Tarchalska’ and traditional foliage cv. ‘Klif’, were studied. A collection of 8446 observations was used to construct a CART regression tree. The CART model allowed us to build a regression tree with 14 terminal nodes and produced a Pearson correlation coefficient, between predicted and actual masses of seeds, of 0.71. The model satisfactorily explained the variation in the mass of a single pea-seed. It was found that the single pea-seed mass is affected mostly by 4 predictors: ‘K index’, which describes the hydrothermal conditions during pea sowing-emergence (K s-e) and emergence-maturity (K e-m) periods, ‘length of pod’ and 'cultivar'. In the CART model, the optimal K s-e index and long pods were always associated with higher seed mass. The mass of a single pea-seed also depended on the ‘Fruiting node’—larger seeds developed on the lowest nodes of a stem. Two factors had a marginal effect on the mass of single pea-seeds: ‘Rhizobium vaccine’ and ‘pod position per node’.

Effect of Seed Size and Position in Pod on the Early Seedling Growth of Fluted Pumpkin (Telfaria occidentalis) in Southwestern Nigeria

Effect of Seed Size and Position in Pod on the Early Seedling Growth of Fluted Pumpkin (Telfaria occidentalis) in Southwestern Nigeria

Epistatic Effects and QTL×Environment Interaction Effects of QTLs for Yield and Agronomic Traits in Soybean

Improving seed yield is an important goal of soybean breeding programs.In this investigation,a soybean SSR genetic linkage map constructed by a total of 447 recombinant inbred lines(RILs) derived from a cross between Jindou 23(cultivar,female parent) and ZDD2315(semi-wild,male parent) and the mixed linear model was used to identify the QTLs of yield and other QTLs for major agronomic traits in a two-year experiment.Nine QTLs bearing additive effects for pod position,plant height,node number on main stem,branch number,stem thickness and yield per plot were mapped in the linkage groups J_2,I,and M.The QTLs of yield per plot,stem thickness,plant height,branch number and node number on main stem showed positive additive effects donated by Jindou 23.Seven pairs of epistatic effects QTLs for pod position,plant height and stem thickness were detected,which had an interaction with environments.The results indicated that the epistatic effects and the environmental factors played an important role in yield per plot and agronomic traits in soybean.It will be very important to pay attention to not only QTLs with major effects but also those with epistatic effects in soybean molecular marker-assisted breeding in considering the stability expression and inheritance of the agronomic traits.