Field Emergence Potential Research Articles

واکنش ژنوتیپهای چند جوانه چغندرقند به تنش شوری

با وجود توسعه کشت مکانیزه و استفاده از ارقام منوژرم چغندرقند در کشور، هنوز در برخی مناطق مانند اراضی دارای تنش شوری و خشکی، استفاده از ارقام چند جوانه به منظور کاهش اثرات سوء محیط و افزایش درصد سبز و استقرار توصیه می‌شود. لذا بررسی ژرم‌پلاسم چند جوانه‌ای چغندرقند تحت تنش شوری ضروری بوده تا بتوان در آینده به ارقام چند جوانه متحمل به شوری دست یافت. برای این منظور، 20 گرده افشان مختلف ابتدا در آزمایشگاه در شرایط بدون تنش و شوری 20 دسی زیمنس برمتر به صورت آزمایش فاکتوریل در قالب طرح کاملا تصادفی با چهار تکرار در دو آزمایش جداگانه از نظر درصد جوانه‌زنی بین کاغذ و روش سریع جوانه‌زنی در ارلن با هم مقایسه شده و سپس در محیط گلخانه در شرایط بدون تنش و شوری 16 دسی زیمنس بر متر با چهار تکرار مورد آزمون قرار گرفتند. نمونه‌برداری حدود دو ماه بعد از اعمال تنش در مرحله هشت برگی (استقرار) انجام وعملکرد تر و خشک اندام هوایی و ریشه و عناصر سدیم و پتاسیم و کربوهیدرات محلول اندازه‌گیری شد. از نظر شاخص پتانسیل ظهور در مزرعه، ژنوتیپ‌های 7233، AMP2 و PB13-S2-151-HSF-915 به ترتیب با مقادیر 0.176، 0.09 و 0.05 دارای بیشترین مقدار این شاخص بودند. شوری باعث کاهش وزن خشک کل، اندام هوایی و ریشه، پتاسیم و کربوهیدرات محلول به ترتیب حدود 20، 24و 6، 42 و 38 درصد و افزایش مقدار سدیم و فسفر برگ به ترتیب حدود 4 برابر و 11 درصد شد و در نهایت ژنوتیپ‌های PB13-S2-151-HSF-915، 7233، S1–930882، S1–931008، Poly8823، S1–930770، Gazale، S1–930910، 5RR-87-HS-28 و S1–930792 بر اساس مجموع صفات جوانه‌زنی به روش سریع و روش بین کاغذ، صفات عملکردی و بیوشیمیایی به عنوان ده ژنوتیپ برتر در تنش شوری انتخاب شدند

Evaluation of Radicle Emergence Test to Predict Seed Vigor and Field Emergence in Different Seed Lots of Cluster bean (Cyamopsis tetragonoloba L.)

The study was conducted to evaluate and correlate the radicle emergence test with other vigour parameters to predict the seed vigour and field emergence potential in ten seed lots of cluster bean with varying vigour. The results showed that the significant differences were observed among the seed lots in terms of physiological parameters viz., speed of germination, germination percentage (GER), root length, shoot length, dry matter production, vigour index, mean just germination time (MJGT), mean germination time (MGT), radicle emergence (RE) and field emergence (FE) and biochemical parameters viz., electrical conductivity of seed leachate (EC) and dehydrogenase activity (DA). Relationship between seed vigour parameters and radicle emergence per cent with 1mm and 2mm radicle length was also evaluated. The highest R2 values were observed in 2 mm length of radicle emergence per cent (R2 values viz., MJGT = 0.8832, MGT = 0.9379, EC = 0.8320, DA = 0.7810, GER = 0.8323 and FE = 0.8796) compared with 1mm length of radicle emergence per cent (R2 values viz., MJGT = 0.8777, MGT = 0.8826, EC = 0.8107, DA = 0.8113, GER = 0.8292 and FE = 0.8699) for most of the seed vigour parameters in ten different seed lots. The study concluded that counting 2 mm radicle emergence at 32 hours could be used for a quick evaluation to assess the seed vigour in terms of field emergence in cluster bean seed lots.

Length of the lag period of germination predicts the vigour differences and field emergence potential in Italian ryegrass (Lolium multiflorum) seed lots

Length of the lag period of germination predicts the vigour differences and field emergence potential in Italian ryegrass (<i>Lolium multiflorum</i>) seed lots

Germination and field emergence potential of soybean land races vs improved varieties under different sowing dates

Poor seed quality resulting in the establishment of poor stand which is the major problem of production in the cultivation of soybean. The objectives behind study were to evaluate the standard germination, field emergence and field emergence index of the seeds obtained from three land races (Kulat brown, Kulat white, Mothi) and two improved varieties (NARC-II, Swat-84) of soybean sown at four different dates at monthly interval from April to July during 2004, 2005 at New Developmental Farm, Agriculture University Peshawar. Standard germination, field emergence and field emergence index were significantly affected by sowing dates and varieties. In addition, to field emergence and field emergence index were observed to be affected by years. Sowing dates x varieties interactions were found significant for field emergence only. Maximum germination (74.6 %), field emergence (60.2 %) and field emergence index (79.1) were recorded for seeds harvested from May, April and April planted crops respectively. Kulat brown exhibited maximum germination (79 %), field emergence (66.1 %) and emergence index (83.6). In land races, germination, field emergence and field emergence index were detected as higher by 39, 58 and 12 percent comparatively to improved varieties. It is concluded that land races have the potential to emerge in various environmental conditions contrasted with improved varieties of soybean. Keywords: Germination; Field emergence; Field emergence index; Soybean land races http://dx.doi.org/10.19045/bspab.2017.60007

Development of breeder-friendly markers for selection of MIPS1 mutations in soybean

Mutations in the d-myo-inositol 3-phosphate synthase 1 gene (MIPS1) in soybean [Glycine max (L.) Merr.] cause modifications to seed phosphorus and carbohydrate content that improve the nutritional value of food and feed. Molecular markers are an efficient tool for breeding MIPS1 mutant germplasm due to reduced seed germination and field emergence potential. An F2 population segregating for the MIPS1 mutation found in experimental soybean line V99-5089 was used to develop breeder-friendly markers. Markers were validated in 88 advanced lines from 9 diverse pedigrees. Ten potential simple sequence repeat (SSR) markers, located on Gm11, from the new BARCSOYSSR_1.0 database were tested and four were polymorphic. BARCSOY_11_1495 was 93–97% effective for selecting the mutation. A KBiosciences Competitive Allele Specific PCR (KASPar) assay was developed to select directly for the V99-5089-derived MIPS1 single nucleotide polymorphism (SNP) mutation. The KASPar assay is simple and cost-effective compared to other SNP genotyping assays. The MIPS1 mutation in V99-5089 is likely to have occurred spontaneously. We describe a method of DNA extraction in soybean using a Geno/Grinder for fast and easy tissue maceration.

Seed Production and Processing

Sugar beet cultivation is highly dependent on the supply of high quality seed as carriers of specific and requested varietal characteristics. Seed production of the biennial sugar beet is conducted in two main phases: the production of small beet plants (stecklings) in the first year of vegetative growth and seed production in the second year after the bolting and flowering of vernalized plants. Optimal conditions for sugar beet seed production are mainly found in regions with a Mediterranean climate. Parental lines in hybrid seed production are specifically handled to ensure a high level of varietal purity and seed quality. Particular post-harvest processing steps and techniques are well integrated to select seed lot fractions with the best quality and the highest field emergence potential. Additionally, seeds are covered by specifically developed pellets to support their placement in sugar beet fields and to act as carriers for plant protection agents. During the last few years an increasing amount of seeds were also subjected to pre-treatments in order to further improve seed quality characteristics for optimal plant establishment in sugar beet production fields.

Transcript profiles uncover temporal and stress-induced changes of metabolic pathways in germinating sugar beet seeds

BackgroundWith a cultivation area of 1.75 Mio ha and sugar yield of 16.7 Mio tons in 2006, sugar beet is a crop of great economic importance in Europe. The productivity of sugar beet is determined significantly by seed vigour and field emergence potential; however, little is known about the molecular mechanisms underlying these traits. Both traits exhibit large variations within sugar beet germplasm that have been difficult to ascribe to either environmental or genetic causes. Among potential targets for trait improvement, an enhancement of stress tolerance is considered because of the high negative influence of environmental stresses on trait parameters. Extending our knowledge of genetic and molecular determinants of sugar beet germination, stress response and adaptation mechanisms would facilitate the detection of new targets for breeding crop with an enhanced field emergence potential.ResultsTo gain insight into the sugar beet germination we initiated an analysis of gene expression in a well emerging sugar beet hybrid showing high germination potential under various environmental conditions. A total of 2,784 ESTs representing 2,251 'unigenes' was generated from dry mature and germinating seeds. Analysis of the temporal expression of these genes during germination under non-stress conditions uncovered drastic transcriptional changes accompanying a shift from quiescent to metabolically active stages of the plant life cycle. Assay of germination under stressful conditions revealed 157 genes showing significantly different expression patterns in response to stress. As deduced from transcriptome data, stress adaptation mechanisms included an alteration in reserve mobilization pathways, an accumulation of the osmoprotectant glycine betaine, late embryogenesis abundant proteins and detoxification enzymes. The observed transcriptional changes are supposed to be regulated by ABA-dependent signal transduction pathway.ConclusionThis study provides an important step toward the understanding of main events and metabolic pathways during germination in sugar beet. The reported alterations of gene expression in response to stress shed light on sugar beet stress adaptation mechanisms. Some of the identified stress-responsive genes provide a new potential source for improvement of sugar beet stress tolerance during germination and field emergence.

Effect of temperature and humidity regimes on grain mold sporulation and seed quality in sorghum (Sorghum bicolor (L.) Moench)

Grain mold, induced by a number of non-specific fungi, causes substantial loss to seed/grain yield and quality in sorghum (Sorghum bicolor (L.) Moench). Fungal sporulation and grain mold severity are greatly influenced by temperature and relative humidity (RH) levels. We studied the effects of three incubation temperatures (25, 27 and 28°C) and two sets of RH levels (first set: 85, 90, 95, 98, and 100%, second set: 95, 96, 97, 98, 99 and 100%) on sporulation and grain mold severity in three major mold fungi (Curvularia lunata, Fusarium moniliforme, and Bipolaris australiensis) and on four each of resistant, moderately resistant and susceptible sorghum genotypes for sporulation and mold severity of major fungi. Results indicated that both fungal sporulation and grain mold severity increased on most sorghum genotypes with increasing incubation temperature from 25 – 28°C and RH levels from 95 – 98%. A linear relationship was observed among RH levels, grain mold severity and fungal sporulation. The highest sporulation of all the three fungi occurred at 28°C and 98% RH after 5 days of incubation. Among the three fungi, C. lunata grew and sporulated faster than B. australiensis and F. moniliforme, in that order. Among the sorghum genotypes, IS 25017 supported the least sporulation and had the lowest mold severity, followed by IS 8545 and PVK 801. Seed quality parameters, such as seed germination, seedling vigor index, field emergence potential, dehydrogenase and ά-amylase activities declined significantly with increasing temperature and RH levels that supported heavy sporulation and grain colonization.

Electrical conductivity of the seed soaking solution and soybean seedling emergence

Vigor of soybean [Glycine max (L.) Merrill] seeds can be evaluated by measuring the electrical conductivity (EC) of the seed soaking solution, which has shown a satisfactory relationship with field seedling emergence, but has not had aproper definition of range yet. This work studies the relationship between EC and soybean seedling emergence both in the field and laboratory conditions, using twenty two seed lots. Seed water content, standard germination and vigor (EC, accelerated aging and cold tests) were evaluated under laboratory conditions using -0.03; -0.20; -0.40 and -0.60 MPa matric potentials, and field seedling emergence was also observed. There was direct relationship between EC and field seedling emergence (FE). Under laboratory conditions, a decreasing relationship was found between EC and FE as water content in the substrate decreased. Relationships between these two parameters were also found when -0.03; -0.20 and -0.40 MPa matric potentials were used. EC tests can be used successfully to evaluate soybean seed vigor and identify lots with higher or lower field emergence potential.

Maintenance and enhancement of germination and vigour in Marigold (Tagetes spp.) seed

Marigold is one of the important annual flowers grown for commercial purposes in India. Non availability of high quality seeds of marigold is one of the major constraints to its cultivation. The present investigations reveal that there is a rapid decline in vigour and viability of marigold seed under ambient conditions of storage from April to October in North Indian plains. Drying seeds to about 8% moisture content and storing in sealed moisture resistant packages resulted in maintenance of satisfactory levels of germination (above 50%) for 6 to 10 months at ambient temperatures, while placing silica gel with seeds in paper packets was effective up to 4 months. When stored at 15 ± 2°C germination could be maintained for 8-10 Months in moisture resistant containers and for 6-8 months in paper packets with silica gel, respectively. Germination (%) after 4 days of accelerated ageing (100%, 40°C) was a good indicator of seed vigour and its field emergence potential. A simple pre-sowing seed hydration treatment (soaking for 24 hours at room temperature) was effective in increasing the speed and the final germination percentage. Slow drying of the hydrated seed over silica gel was preferred over sun drying, which was detrimental to seed quality.

Seed Source Effect on Field Emergence of Soybean Lines with Reduced Phytate and Raffinose Saccharides

Soybean [Glycine max (L.) Merr.] lines homozygous for the mips allele (mips lines) have reduced phytate P and raffinose saccharides in the protein meal. Less phytate is desirable for reducing the P content of manure from nonruminant animals and less raffinose saccharides increases the amount of metabolizable energy available to them. Field trials indicated that seedling emergence percentage of mips lines was less for seed produced in a subtropical environment than a temperate environment. The objective of this study was to determine if field emergence of mips lines is influenced by the environment used for seed production. Seed of six mips lines and four commercial cultivars (Mips lines) produced in four temperate and 12 subtropical environments during 2 yr was evaluated for field emergence percentage, seed viability percentage, and germination percentage in warm germination, cold vigor, and accelerated aging tests. The field emergence percentage of mips lines was significantly less than Mips lines for all seed sources. The mips lines had a mean field emergence of 63% for temperate sources and 8% for subtropical sources while Mips lines had a mean field emergence of 77% for temperate sources and 83% for subtropical sources. The mean seed viability percentage for the mips lines based on the tetrazolium test of 88% for temperate sources and 70% for subtropical sources accounted for only part of the differences in field emergence. Differences in field emergence between the mips and Mips lines were not consistently predicted by the warm germination and cold vigor tests for temperate sources. The accelerated aging test effectively differentiated the field emergence potential of the mips and Mips lines for all seed sources. Seed source should be a consideration when evaluating the field emergence of mips lines in a breeding program or for obtaining acceptable plant populations in commercial fields.

Cultivar-specific seedling vigor and expression of a putative oxalate oxidase germin-like protein in sugar beet (Beta vulgaris L.).

For genetic screening and breeding purposes, an in vitro germination system that reflects relative field emergence potential was used to screen for germination-enhancing and stress-induced genes from germinating seedlings from two varieties of sugar beet. Three full-length germin-like protein (GLP) gene classes were recovered from stress-germinated seedlings of a superior emerging variety. GLP gene expression, oxalate oxidase protein activity, the H(2)O(2) content of stressed seedlings, but not catalase activity, were induced by stress germination conditions (e.g. excess water, NaCl, mannitol, or oxalate) in a good emerging hybrid and were not induced in a poor emerging variety. Only one of the three germin-like protein genes ( BvGer165) was differentially regulated, and was induced only in the good emerger. Hydrogen peroxide promoted germination and partially compensated solute-depressed germination percentages. Unlike other solute recovery by hydrogen peroxide regimes, recovery in oxalic acid plus H(2)O(2) was cultivar-independent. A block in oxalate metabolism is postulated to contribute to lower germination under stress in the lower emerging variety. Selection for stress-induced germin expression, or for down-stream targets, presents the first direct target to enable breeding for improved field emergence of sugar beet.

Relationship between Laboratory Seed Quality Tests and Field Emergence of Common Bean Seed

In cool climates, early planting of bean (Phaseolis vulgaris L.) is recommended to assure a longer vegetative growth period. Early planting exposes seed to unfavorable conditions and the commonly used standard germination test cannot predict field emergence. The objective of this work was to examine the relationships between various seed quality tests and field emergence of common bean seeds. Thirty‐nine strains and cultivars of bean were tested in the field and laboratory over 3 yr. Each year seed samples were tested in the laboratory and then planted in the field at very early, early, and at optimal planting dates. The viability of seeds was test by tetrazolium staining and was generally high; standard germination was above 80%, but germination in the cool test (at 10°C) varied from 0 to 99%. The percentage of seeds with broken coats varied from 0.5 to 50.3 and conductivity ranged from 7 to 45 μS cm−1 g−1. Field emergence varied from 0 to 100%. Soil temperature at sowing appeared to be not only the most important environmental factor influencing field emergence but also a factor able to be used to differentiate the field emergence potential of a seed lot. Only the conductivity test could be used to predict seedling emergence in the field irrespective of soil temperature at sowing. At temperatures ranging from 9 to 15°C, the first and the last count of the standard germination test and the broken seed coat test should be used in conjunction with the conductivity test to estimate field emergence potential.

Qualidade fisiológica e comportamento de sementes de soja (Glycine max (L.) Merrill) no armazenamento e no campo

A presente pesquisa, conduzida, entre 1981 e 1985 no Departamento de Agricultura e Horticultura da Escola Superior de Agricultura "Luiz de Queiroz" - USP, constou de colheita, em diferentes épocas, de campos de sementes dos cultivares IAC-Foscarin 31 (precoce) e IAC-8 (semi-tardio). Os materiais coletados foram, em seguida, armazenados em câmara seca, câmara fria e ambiente normal; periodicamente, com intervalos bimestrais, conduziram-se testes de germinação, envelhecimento acelerado, conduti-vidade elétrica e emergência das plântuIas, além de ensaios de campo instalados em época normal de semeadura para a cultura da soja. Observou-se que os testes realizados em laboratório, com destaque para o de condutividade elétrica, mostraram-se eficientes para diferenciar níveis de qualidade fisiológica e estimar o potencial de emergência das plântulas; sementes do cultivar precoce apresentaram qualidade fisiológica inferior às do semi-tardio, fato atribuído às condições climáticas adversas predominantes durante o final do ciclo das plantas. A umidade relativa do ambiente e a qualidade fisiológica inicial constituiram-se em fatores preponderantes no potencial de conservação das sementes.

Influence of Seed Size on Seed Quality of Sorghum

Five seed size classes of sorghum CSH 5 hybrid and its parents, CS 3541, ms 2077 A and 2077 8 were studied for the relative differences in seed quality. The 1000-seed weight, seed volume and specific gravity of seeds showed distinct and significant differences among seed sizes. The germination and field emergence potential of 10, 9 and 8 retained seeds were significantly higher than those from 7 and 5 retained seeds. The seedling vigour ass- essed by seedling growth measurements and dry matter estimation in plant parts and the vigour index values amply showed the superiority of the large and medium size seeds over the smaller ones. The study had revealed that the optimum sieve size is 8/64" round per- forated metal sieve for processing the seed lots of sorghum CSH 5 hybrid and its parental lines.

Heritability and Advance from Selection for Six Soybean Seed‐quality Characters1

Seed harvested from F3, F5, and F6 lines of six soybean [Glycine max (L) Merr.] crosses were evaluated for field emergence percentage and visually rated for defective seedcoat, wrinkled seedcoat, shriveled cotyledons, green cotyledons, and overall appearance. Correlations between field emergence percentage and the visually rated characters were low, although low incidence and severity of the visually rated characters were generally associated with high field‐emergence percentages. The overall rating generally was equal to any other rating as an indicator of relative field emergence.Heritability estimates for field‐emergence percentage were low, due to low genetic variability for the character in the F5 and F6 generations and to the large error associated with estimating the field emergence potential of a seed lot. Estimates of heritability for the visual ratings generally were higher than for field emergence, with heritability of green cotyledons usually being lower than the other visually rated characters.Selecting for high field‐emergence percentage resulted in no significant advance for the character. Advances from selection were somewhat higher for the visually rated characters. The results of this and previous studies suggest that the most efficient means of improving soybean seed quality in a breeding program is to use an overall visual rating and a laboratory germination test in which normal seedlings are counted early in the germinating period, probably at 5 days. An alternative method is to concentrate on improving visually rated characters by selection when environmental conditions cause adequate expressivity.