Rapid seed germination and stand establishment are critical factors to crop production under salt‐stress conditions. In many crop species, seed germination and early seedling growth are the most sensitive stages to salinity stress. Salinity may delay the onset, reduce the rate, and increase the dispersion of germination events, leading to reductions in plant growth and final crop yield. The adverse effects of salt‐stress can be alleviated by various measures, including seed priming (a.k.a. pre‐sowing seed treatment). The general purpose of seed priming is to partially hydrate the seed to a point where germination processes are begun but not completed. Most priming treatments involve imbibing seed with restricted amounts of water to allow sufficient hydration and advancement of metabolic processes but preventing germination or loss of desiccation tolerance. Treated seeds are usually redried before use, but they would exhibit rapid germination when re‐imbibed under normal or stress conditions. Various seed priming techniques have been developed, including hydropriming (soaking in water), halopriming (soaking in inorganic salt solutions), osmopriming (soaking in solutions of different organic osmotica), thermopriming (treatment of seed with low or high temperatures), solid matrix priming (treatment of seed with solid matrices), and biopriming (hydration using biological compounds). Each treatment has advantages and disadvantages and may have varying effects depending upon plant species, stage of plant development, concentration/dose of priming agent, and incubation period. In this article, we review, evaluate, and compare effects of various methods of seed priming in improving germination of different plant species under saline and non‐saline conditions. We also discuss the known metabolic and ultra‐structural changes that occur during seed priming and subsequent germination. To maximize the utility of various seed priming techniques, factors affecting their efficiency must be examined and potential benefits and drawbacks determined. For example, quality of the seed before treatment, concentration/dose of priming agent, time period for priming, and storage quality of the seed following priming treatment must be carefully determined. Furthermore, such assessments must be based on large‐scale experiments if seed priming is to be used for large‐scale field planting. A better understanding of the metabolic events that take place in the seed during priming and subsequent germination will improve the effective application of this technology. The incorporation of advanced molecular biology techniques in seed research is vital to the understanding and integration of multiple metabolic processes that can lead to enhanced seed germination, and consequently to improved stand establishment and crop yield under saline and non‐saline conditions.

Pre‐Sowing Seed Treatment—A Shotgun Approach to Improve Germination, Plant Growth, and Crop Yield Under Saline and Non‐Saline Conditions

Nonpathogenic rhizobacteria can induce a systemic resistance in plants that is phenotypically similar to pathogen induced systemic acquired resistance Rhizobacteria mediated induced systemic resistance has been demonstrated against fungi,bacteria,and viruses in Arabidopis,bean,camation,cucumber,radish,tobacco and tomato under conditions in which the inducing bacteria and the challenging pathogen remained spatially separated Bacteria induce plants to produce the JA and ethylene to develop the ISR And ISR is effective under field conditions and offers a natural mechanism for biological control of plant disease

Systemic resistance induced by rhizosphere bacteria

Priming applied to commercial seed lots is widely used by seed technologists to enhance seed vigour in terms of germination potential and increased stress tolerance. Priming can be also valuable to seed bank operators who need improved protocols of ex situ conservation of germplasm collections (crop and native species). Depending on plant species, seed morphology and physiology, different priming treatments can be applied, all of them triggering the so-called ‘pre-germinative metabolism’. This physiological process takes place during early seed imbibition and includes the seed repair response (activation of DNA repair pathways and antioxidant mechanisms), essential to preserve genome integrity, ensuring proper germination and seedling development. The review provides an overview of priming technology, describing the range of physical–chemical and biological treatments currently available. Optimised priming protocols can be designed using the ‘hydrotime concept’ analysis which provides the theoretical bases for assessing the relationship between water potential and germination rate. Despite the efforts so far reported to further improve seed priming, novel ideas and cutting-edge investigations need to be brought into this technological sector of agri-seed industry. Multidisciplinary translational research combining digital, bioinformatic and molecular tools will significantly contribute to expand the range of priming applications to other relevant commercial sectors, e.g. the native seed market.

Seed priming: state of the art and new perspectives.

Growers expect high-quality, genetically pure seed. As a result, seed companies maintain quality control programmes that monitor seed from harvest to purchase. An array of ‘traditional’ seed quality tests, including mechanical tests and tests of genetic purity, seed germination and vigour, and seed health tests, is used, and seed quality assessment techniques continue to evolve. Advances in molecular genetics are allowing the release of new varieties differing essentially in one gene. New molecular biology approaches offer the potential to identify these subtle genetic differences. Advances in seed enhancements, such as pelleting, priming and pregermination, require increased scrutiny of seed quality before and after the enhancement process. New developments in computer imaging for improved purity and germination/vigour analyses are being developed. These novel approaches to seed quality assessment become important as new genetic improvements are conveyed in the seed at increased cost to the grower.

https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0960258500004165

Seed quality assessment

Presowing Seed Priming

A matricondition ing procedure based on the matric properties of Micro-Cel E and expanded vermiculite #5 has proved effective in improving seedling emergence in growth chambers. The major objectives of this study were to examine some physical characteristics of the carriers and their effectiveness as preplant conditioning media in improving stand establishment of vegetable seeds in field plantings. Carrier characteristics included no detectable solute or osmotic potential, low electrical conductivity (0.48-0.04 mmho/cm), high water-retaining capacity (450% to 600%), a pH range of 7.0 to 8.4, and ability to effectively control seed hydration (conditioning) at low matric potential. The seed : carrier : water ratio for seed conditioning ranged from 1:0.3-0.5:1-2 (by weight). In a field trial, condi- tioning of 'Long Imperator' and 'Nantes' carrot (Daucus carota var. sativus Hoffm.) seeds reduced the time to 10% of final emergence (T1O) by 2.6 to 2.8 days and to 50% of final emergence (T 50) by 2.1 to 3.0 days. Conditioning increased the final emergence percentage by 39% in 1-year-old 'Long Imperator' compared to 150% in 4-year-old 'Nantes' seeds. In another field trial, the effect of conditioning on stand establishment was evaluated in 'Jackpot' tomato (Lycopersicon esculentum Mill.), 'California Wonder' pepper (Capsicum annuum L.), and 'BBL 47' snap bean (Phaseolus vulgaris) seeds. In tomato, conditioning reduced the T 10 by 0.9 day, had no effect on T 50, and increased the emergence percentage by 86%. In pepper, conditioning reduced the T 10 and T50 by 1.5 days and increased the percentage emergence by 30%. In snap bean seeds, conditioning in Micro-Ccl E reduced the T 1O and T50 by 0.8 day but adversely affected the percentage emergence. Further reductions in T 10 and T50 (1.2 and 1.6 days, respectively) and restoration of percentage emergence to control level occurred upon addition of 0.001 mM GA 3 during conditioning. Fungicides added to carrot, tomato, and pepper seeds, with or without conditioning, showed no additional improve- ments and, in a few cases, adversely affected emergence. A preplant conditioning in Micro-Ccl E, alone or in combination with GA3, smears to be a viable alternative to conditioning! seeds in liquid carriers. Chemical name used: gibberellic acid (GA3 ) Osmoconditioning or priming of seeds in solutions of low water potential, e.g., polyethylene glycol (PEG) and salts, has been used extensively as a preplant seed treatment to reduce germination or seedling emergence time, synchronize emer- gence, and improve stand establishment and yield (Bradford, 1986; Heydecker and Coolbear, 1977; Khan, 1991; Khan et al., 1978). A preplant seed conditioning has also been achieved by mixing seeds with moist solid or semisolid carriers (e.g., ver- miculite, expanded calcined clay, Agro-Lig, sodium polypro- pionate gel, synthetic calcium silicates) (Bennett and Waters, 1987; Callan et al., 1990; Khan et al., 1990; Kubik et al., 1988; Parera and Cantliffe, 1990; Peterson, 1976; Taylor et al., 1988; Zuo et al., 1988). Postplant conditioning of beet seeds in moist soil microenvironment in the field has been achieved by incor- porating PEG into solid material used for seed pelleting, as indicated by improved emergence and yield (Khan and Taylor, 1986). Hydration or conditioning of seeds can be regulated by os- motic and/or matric components of the carrier matrix water po- tential. The water potential component(s) of the carrier can be

/pdf/matriconditioning-of-vegetable-seeds-to-improve-stand-31b639631i.pdf

Matriconditioning of Vegetable Seeds to Improve Stand Establishment in Early Field Plantings

ILMU DAN TEKNOLOGI BENIH : Teori dan Hasil-hasil Penelitian

Sowing seed of high quality is necessary for commercial crop production. Poor quality seeds will result in low field emergence and in seedlings that are less tolerant to abiotic stress, more sensitive to plant diseases, and will reduce the quality and yield of crops produced. With the use of good seeds, one gets better results with less effort and expense. High seed quality is characterized by high analytical purity. The seeds must be free of seeds of other species and varieties, weed seeds and inert matters. High vigor and germination capacity are the other characteristics of high seed quality. Another important attribute is free from seedborne disease. Vegetable farmers experience losses due to pathogen problem during plant production affected by use of infected seeds. Seed pathogens are often the primary agents responsible for low seed quality and poor stand establishment. Seed is an effective means of disease dissemination. One infected seed can infect many plants in a seedbed before they are transplanted to the field. A few infected plants in the field can provide the source of inoculum to spread the disease to other plants (AVRDC, 1990). The presence of seedborne pathogens in the seeds will either prevent the germination, or may result in disease epidemics due to transmission of the diseasecausing pathogen from seed to the plant. This will have a negative impact on the quality and yield of crops produced. Therefore, it is important to use healthy seeds from the beginning. An effort to develop various seed treatments to overcome seedborne pathogens may provide an opportunity to optimize seed quality, and improve plant stand eventually. This article is written based on the author’s research with her students studied on seed science and technology as their thesis or dissertation, particularly with emphasis on vegetable seed quality improvement. VARIOUS SEED TREATMENTS TO IMPROVE SEED QUALITY AND HEALTH, PLANT STAND AND YIELD

/pdf/review-seed-treatments-using-matriconditioning-to-improve-4ykteguvsq.pdf

Review : Seed Treatments Using Matriconditioning to Improve Vegetable Seed Quality

Integrating low water potential seed hydration with other treatments to improve cold tolerance

The development of hybrid varieties should be supported by the availability of high quality seeds. Genetic purity is one of the quality criteria required for successful seed production of maize hybrid. In producing hybrid seeds, it is frequently contaminated by crossed pollen from another variety or the occurrence of selfing. The objectives of this study were 1) to get microsatellite markers (SSR) specific for male and female parents, 2) to get a percentage of the genetic purity of maize hybrid seeds cv. Bima-3 and Bima-4. The experiments were conducted at field station at University Farm Cikabayan Bogor Agricultural University, and in the molecular laboratory at Indonesian Center for Agricultural Biotechnology and Genetic Resources Bogor, from April until December 2011. Maize hybrid varieties and their parental lines seed used in this research were obtained from Indonesian Cereal Research Institute (ICERI) Maros, South Sulawesi. Five SSR markers selected for parental lines were phi109275, phi96100, phi374118, phi328175, and phi072. The assessment of genetic purity of two hybrid varieties namely cv. Bima-3 and Bima-4, used specific markers from previous experiment. Fourty samples of individual plants from each maize hybrid variety were tested. From five markers tested, three markers namely phi96100, phi328175 and phi072 produced polymorphic bands and capable to distinguish parental line of two maize hybrids. Microsatellite marker phi96100 was specifically used for testing genetic purity of cv. Bima-4 and phi072 for cv. Bima-3. While phi328175 was specific marker for both maize hybrids. The genetic purity test of cv. Bima-3 and Bima-4 indicated that both varieties had purity levels of 97.5% and 80%, respectivelly. This study showed that SSR markers were more reliable for assessing genetic purity as compared to morphological marker. The results of study are expected to be useful in the verification of genetic purity of maize hybrid seeds accuretly.

/pdf/seed-genetic-purity-assessment-of-maize-hybrid-using-kyv2vc189a.pdf

Satriyas Ilyas

Papers

Matriconditioning of Vegetable Seeds to Improve Stand Establishment in Early Field Plantings

ILMU DAN TEKNOLOGI BENIH : Teori dan Hasil-hasil Penelitian

Review : Seed Treatments Using Matriconditioning to Improve Vegetable Seed Quality

Integrating low water potential seed hydration with other treatments to improve cold tolerance

Seed Genetic Purity Assessment of Maize Hybrid Using Microsatellite Markers (SSR)