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Seed processing is specialized activity and also a tool to improve seed quality further to an acceptable standard. Seed quality parameters like germination, vigour or genetic purity can be improved using processing. Say a seed lot having a minimum standard of 90% germination, but the competition in the market offering seed quality 92 or 95 % then to meet the market demand we can process the seed lots using re-milling or re-conditioning techniques. Also sometimes simple techniques like liquid density separation which uses specific density of the seed to separate good seed from inferior quality can be considered.

The physical properties of seeds are a basic activity for designing processing equipments and precision planters. Since these characters vary with crop or variety, one needs to have the data handy to be used on shop floor. This data also helps to quantify processing efficiency, presence of dormancy and suitability for seed treatments for all existing and new crops or varieties.

ABSTRACT

Wood apple is a hardy tree grown in arid and semiarid regions of the country. It is generally propagated through seeds. The traditional methods like budding and inarch grafting require 9 to 12 months for the root stock to come buddable size and thus 1½ to 2 years to become ready for transplanting. The present study was initiated to prepare a grafts within eight months by adopting the micrografting technique. The seeds were sown in the month of April in polybags filled with FYM, sand and soil in equal proportions with a pinch of blitox. The micrografting was done on 1½, 2, 2½ and 3 month old seedling root stock having a diameter of 0.13 to 0.15 cm, 0.17 to 0.19 cm, 0.20 to 0.22 cm and 0.23 to 0.26 cm, respectively. The seedling root stocks were decapitated with the surgical blade and 1 to 2 cm deep split was made. The scion micro bud (1 to 2 cm length and 1 to 2 mm width) of previous season’s growth was inserted in the split. The micropipette cap (0-200 μl) was inserted on the grafted portion. After sprouting of the micro bud, the micro pipette cap was removed. The study revealed that, micro bud grafting success was significantly influenced by the root stock age. Early bud take was observed when the micrografting was done on 2½ month (10.73 days) and 3-month (11.00 days) old root stock. The percent bud take on 3-month old root stock was significantly higher (99.33 per cent) than the rest of root stocks. Micrografting done on 3-month old seedling root stocks in June-July is suggested for quick multiplication of woodapple.

ABSTRACT

Attempts were made to induce variability by irradiation of axillary buds of rose cv. Folklore followed by in vitro culture. Axillary bud explants collected at different growth stages were subjected to gamma irradiation at different doses (20, 30 and 40 Gray). The in vitro induced micro shoots were sub cultured on a rooting medium (M.S. basal medium supplemented with IAA 1.00 mg/l + NAA 1.00 mg/l + activated charcoal 500 mg/l). The rooting percentage was the lowest in explants irradiated with 40 Gy. Rooting efficiency was severely affected when buds were collected at vegetative phase. Significant interaction between bud stages and gamma rays was noticed for days to root initiation and number of roots per culture. Gamma irradiation at 30 and 40 Gy significantly delayed root initiation at all stages of buds exposed. Significant reduction in number of roots/ culture, and root length was observed at higher doses of gamma exposure. The reduced rooting efficiency may be due to inhibition of cell division on account of chromosome damage.

Fusarium wilt of carnation caused by Fusarium oxysporum f.spp dianthi causes severe yield losses under protected cultivation. For the management of Fusarium wilt, 27 isolates of Bacillus strains were isolated from the rhizosphere of different crops including carnation. Among various species of Bacillus, Bacillus amyloliquefaciens (BSC7) was identified as a most virulent antagonistic bacterial isolate. Studies on antagonism under Environmentally Controlled Scanning Electron Microscopy (ESEM), depicted the presence of rod shaped bacterial cells with biofilm formation at 44847x. Detection for the presence of antibiotic biosynthetic genes reflected the presence of surfactin, iturin, bacillomycin and fengycin genes. The 24 isolates of Bacillus spp. showed positive reaction for surfactin gene. Nineteen isolates were amplified for Iturin A gene except BS5, BS9, BSC1, BSC2, BSC11, BSD1 and BSD2. Strains of B. subtilis BS1, BS2, BS5, BS6 and BS8 expressed Bacillomycin D gene. The genomic DNA of strains BS1, BS2, BS4, BS6, BS7 BS8, BS11 and BS14 showed positive for Fengycin D gene. The isolate of B. subtilis BS2 showed positive reaction for four genes namely surfactin, iturin, bacillomycin and fengycin.

In vitro screening of Bacillus, B. amyloliquefaciens (BSC7), P. aeruginosa (P1) and T. viride (TV1) showed highest inhibition against F.oxysporum f.sp.dianthi to an extent of 55.95, 55.29 and 81.61 per cent over the control respectively. The antifungal activity of antagonistic B. amyloliquefaciens BSC7 and T. viride TV1 against F.oxysporum f.sp. dianthi was confirmed under ESEM by observing disintegration, lysis and structural abnormalities of the hyphae of the pathogen at the zone of interaction.

Abstract

The relationship between development of P. leucotricha with different weather parameters (i.e. temperature, relative humidity and rainfall) was ascertained by computing multiple regression equations between these factors along with coefficient of determination (R2). Multiple regression analysis revealed that weather parameters altogether accounted for 31.88 to 94.45 per cent variations in Shimla district (Himachal Pradesh) during 2002-03. The accumulated variation due to weather parameters during the years accounted to different levels of primary inoculum and infection conditions under the field conditions.

Abstract

The studies were conducted during the years 2002 and 2003, to standardize the best method and time for summer budding in walnut. Four methods of summer budding viz. chip, annular, patch and shield were performed at 10 days interval from 15th May to 24th July. The results revealed that among the four methods of summer budding, chip budding was found to be highly superior to other methods of budding and gave 92% bud take success on 25th May and 87 per cent on 15th May also. Annular budding performed on 14th June was found next superior method and time of budding for walnut propagation when it resulted in 81% bud take success. Chip budded plants attained maximum height and radial growth as compared to annular and patch budded plants. The period from mid of May to first week of June was considered as optimum time for chip budding and mid June to end of June for annular and patch budding for walnut propagation under mid hill conditions of North-western Himalayas.

ABSTRACT

Protoplast isolation of Piper nigrum L.and Piper colubrinum Link. was attempted using axenic leaves at two different osmotic potentials viz. 0.60 and 0.65 molar (M) osmoticum. In Piper nigrum, highest protoplast yield (6.90 x 10⁴ protoplasts ml^-1) was observed in the enzyme combination 1.40 per cent cellulase and 0.310 per cent pectinase while in Piper colubrinum, highest protoplast yield (13.0 x 10⁴ protoplasts ml^-1) was observed in the enzyme combination 1.0 per cent cellulase and 0.217 per cent pectinase during 21 h of digestion. In both the species, 0.6 M osmoticum was found to be optimum to maintain the osmotic potential of the isolation solution. Filtration-centrifugation technique was found to be superior in purifying the protoplasts of Piper species compared to sucrose floatation method. Centrifugation at 1000 rpm for three minutes was found to be best in purifying Piper nigrum protoplasts. For purifying Piper colubrinum protoplasts, 600 rpm for three minutes was found optimum. The protocol developed for protoplast isolation in Piper species can be used for biotechnological means like somatic hybridization between the two and gene transfer to develop foot rot resistant black pepper lines.

Abstract

Old walnut seedlings in the age of up to twenty years were top worked using chip budding technique. In the seedling plants up to ten years of age, budding was done on older branches. But in the seedlings between 10-20 years of age, main branches were first dehorned during winters and the budding was performed on newly emerged branches in the month of May and June. Best results in the seedlings up to 10 years of age was obtained when budding was done in the second week of June with 89 and 97 per cent success in the year 2002 and 2003, respectively. The lowest success, however, was recorded in the plants between 10-20 years of age when budding was performed in the third week of May. Budding success in the plants between 10-20 years of age was slightly lower but they grew very fast as compared to those below ten years of age. Therefore, chip budding can be successfully utilized for the top working of old walnut seeding plants during second week of June when the buds become fully developed. For other areas this date may be different depending upon the maturity of the buds.

Previous Year Questions

1. What is DNA fingerprinting? Discuss the applied aspects in modern agriculture. (15M, CSE 2021)

• The term DNA fingerprinting in its original sense refers to the method developed in 1985 by Sir Alec Jeffreys (Jeffreys et al., 1985) and his associates for the simultaneous detection of highly variable DNA fragments by hybridisation of specific multilocus probes to electrophoretically separated restriction fragments?

• The DNA fingerprints, resembling barcodes, are unique to the individual and hence can be used in much the same way as conventional fingerprints - to identify individuals with absolute certainty?

DNA Fingerprinting Techniques

• A large number of fingerprinting techniques are in currency, which are variations and combinations of restriction fragmentation and polymerase chain reaction (PCR).

• Restriction fragment length polymorphism (RFLP) involves digesting DNA with restriction enzymes, separating the resultant DNA fragments by gel electrophoresis, blotting the fragments to a filter and hybridising probes to the separated fragments. Specific probe-enzyme combinations give highly reproducible patterns.

• With the advent of PCR technology a number of simpler techniques have become available for molecular characterisation.

• These include, random amplified polymorphic DNA (RAPD) and its several variants, intersimple sequence repeats (ISSR), amplified fragment length polymorphism (AFLP) and sequence tagged microsatellites sites (STMS).

Drying is an important unit operation in seed processing in order to maintain seed ability and vigor . it is advocated that seeds should be harvested soon after they attain physiological maturity to obtain better quality seeds and to minimize field losses. The traditional method of sun drying is inadequate, uncontrolled and time bound, which may not meet the high demand of quality seeds in time. Hence artificial drying, the effect of certain drying parameters like seed moisture content, drying air temperature, airflow rate, depth of seed loading and time of exposure on drying characteristics and viability of seeds are to be determined for safe and economical drying of seeds.

ABSTRACT

Cultivated turmeric consists of fertile short duration types with a chromosome number of 2n=84. In vivo crossing was done between two short duration types VK 70 and VK76 to develop a high yielding variety with high curcumin and curing percentage. Seed set and seed development was obtained by in vivo stigmatic pollination. Hybrid seed germination was obtained under in vitro in dark on moist filter paper and the seedlings were micropropagated to establish a population of six plantlets /seedling with in a period of 10 months. The multiple shoots were obtained in the medium of half strength MS + 3 per cent sucrose+ BA 2.5 mg l^-1+ NAA 0.5 mgl^-1. Coupling conventional breeding with tissue culture reduces the breeding time.

ABSTRACT

Protoplast isolation in orchids is considered to be a valuable tool for introduction of desirable traits through somatic cell fusion. The present work on the protoplast in Dendrobium var.sonia is undertaken with a view to standardize protocol for isolation and regeneration. Tender leaf mesophyll tissues of one-month-old Dendrobium var.sonia were used as explant for protoplast isolation. The leaf tissues were treated with enzyme mixture of cellulase 1per cent (Onozuka -R from Trichoderma viride) and macerase 0.25per cent (from Aspergillus niger) for 16 hours. Protoplast from the Dendrobium var. sonia was successfully isolated and regeneration of shoots and roots were obtained in MS medium containing BA 5mg l^-1+NAA 1mg l^-1.The plantlets were hardened in a span of five months.

Seed Priming is the process of controlled hydration of seeds to a level that permits pre-germinative metabolic actively to proceed, but prevents actual emergence of the radical. It is done to increase the speed and uniformity of germination particularly under adverse conditions of temperature, moisture and salinity conditions. In this condition, seeds go through all the essential preparatory processes of germination but prevent cell elongation and radical emergence. During the waiting period at the osmotic barrier the ‘slower’ seeds tend to catch up with the ‘faster ones’ so that the subsequent germination is more uniform, than that of untreated seeds. The duration of priming varies with the crop as well as method of priming such that priming is allowed for I and II stage of seed imbibitions without allowing radical protrusion.

ABSTRACT

Aprotocol for in vitro clonal multiplication of Dendrobium var. Betty Ho is reported. Aseptic shoot tip explants cultured in MS medium containing Benzyl Adenine (5 mg l^-1) and casein hydrolysate (1000 mg l^-1) recorded a maximum multiplication rate of 10 fold in 30 days. Explant cultured in LS) medium supplemented with 1-napthalene acetic acid (0.1 mg l^-1) and Kinetinetin (1 mg l^-1) developed a maximum of 8.3 shoots in 30 days. Shoots thus obtained were rooted on MS medium supplemented with BA (0. 1mg l^-1 ) and NAA (0.5mg l^-1). Rooted plantlets after hardening were transferred to green house.

The objective of seed pelleting is to provide an opportunity to package effective quantities of materials such that they can influence the micro-environment of each seed.
 
Process of Pelleting

Seeds are introduced into a coating drum or pan that resembles a cement mixer. An amalgam of pelleting materials (clays, limestone, calcium carbonate, talc, vermiculite) and cementing adhesives (gum Arabic, gelatine, methyl cellulose polyvinyl alchol) are used to form the pellet and other compounds such as inoculants, fungicides, etc. May be added to enhance seed performance.

ABSTRACT

Plants as a source of medicine are of special importance in the countries like India which has well developed traditional system of medicine which derive more than 90 per cent of medicaments from higher plants. Several of these also constitute important ingredients of Allopathic medicines. Most of the requirements for the medicinal plants are met from wild sources. But due to the changing ecological factors in the forests and unserupulous collection of medicinal plants, the wealth of medicinal plants is getting depleted and some types have already become extinct. The collection of these plants from the forests cannot cope up with the ever increasing and changing demand from the pharmaceutical, perfumery and cosmetic industry. In order to provide regular and sustained supply of medicinal plants, it is essential now to domesticate and systematically cultivate these plants for which large scale availability of planting material has to be ensured. In this context, in vitro multiplication protocols were standardised for rare, valuable and endangered medicinal plants such as Holostemma ada-kodien, Trichopus zylanicus, Aristolichia indica and Terminalia chebula. The study indicates the feasiblity of rapid multiplication of these plant species using in vitro techniques and the standardised protocols could be used to generate large number of true to type protocols within a short time.

Abstract

During inspection of several lily plantations under cover in different districts of Himachal Pradesh plants with severe disease symptoms were observed. The affected plants showed a progressive loss of vigor, were stunted and had a severely malformed leaves. These symptoms were observed on large scale mainly in oriental lily hybrids ‘Acapulaco’. The plants were suspected to be infected with phytoplasma, the presence of which was demonstrated with fluorescent microscopy (DAPI stain). The phytoplasma etiology was further confirmed by conducting nested polymerase chain reaction (PCR) assays using universal primer pairs P1/P7 followed by R16F2n/R16R2, which amplified a fragment of phytoplasma 16SrDNA. This is the first report of phytoplasma infection in lilies identified by molecular assays from India.

ABSTRACT

Medicinal plants are the most important source of life saving drugs for the majority of the world’s population. Therefore the biotechnological tools are important to select, multiply and conserve the critical genotypes of medicinal plants. With the increase in the demand for the crude drugs, the plants are being overexploited, threatening the survival of many rare species. Also, many medicinal plant species are disappearing at an alarming rate due to rapid agricultural and urban development, uncontrolled deforestation, and indiscriminate collection. Advanced biotechnological methods of culturing plant cells and tissues should provide new means for conserving and rapidly propagating valuable, rare, and endangered medicinal plants. Maintenance of germplasm in the green house or in the field has many difficulties and so there is a need for the in vitro conservation of these plant germplasm. In the present paper we report the in vitro conservation of two medicinal plants and each of it has its own medicinal value. The tuberous roots of Holostemma are medicinally important and are utilized as a major ingredient of the drug ‘jivanthi’. Tylophora is used as a herbal medicine and the plant has been traditionally used as a folk remedy for the treatment of bronchial asthma, bronchitis and dermatitis. Shoot buds of these plants were cultured in Murashige and Skoog’s (1962) medium with different strengths and with different concentrations of sucrose and mannitol. The different treatments induced varied response with respect to the slowing of growth of cultures. Sucrose was found essential in combination with mannitol to induce maximum reduction in the growth of the plant tissues. The cultures could be maintained without sub culturing for over one year and resumed normal growth on transfer to mannitol free medium. This method of conservation has many advantages.

Amaranthus is one of the main genera of large and taxonomically diverse group of leafy vegetables. Amaranthus is the cheapest dark green leafy vegetable because of low production costs and high yield. It is often described as poor man’s vegetable.

Origin and Distribution: The main vegetable type Amaranthus tricolor L. originated in South or South East Asia, particularly in India. Budhist monks and Muslim invaders took the crop to neighboring countries. Another vegetable type A. dubius shows diversity in Central America, Indonesia, India and in Africa. A lividus is a popular leafy vegetable in Southern and Central Europe. Amaranthus included 50 to 60 species.