Nutritional characterization and chemical composition of Diplazium maximum (D. Don) C. Chr.

Diplazium maximum (D. Don) C. Chr. is a wild edible fern, traditionally consumed in the tribal areas of western Himalayas. The edible part of the plant (young fronds) was analyzed for its nutritional and phytochemical composition. The dried young fronds (DYF) were found to have high contents of dietary fibre (38.32 g/100 g dry basis) and crude protein (25.39 g/100 g dry basis). Branched-chain-essential-amino acids, polyunsaturated fatty acids (PUFA) (constituting more than 50% of total fatty acids), dihomo-gamma-linolenic acid (unique omega-6 PUFA) and phenolics like epicatechin, myricetin, catechin and procatechuic acid were present in nutritionally significant amounts. Hydro-alcoholic extracts of the DYF contained maximum distribution of polyphenols and flavonoids and exhibited high antioxidant capacities. Analysis of functional properties of DYF such as water and oil absorption capacity, dispersibility and swelling capacity indicated its potential application in instant convenience food products such as soup mixes. Sensory scores of soup mix prepared using DYF was similar to that of commercially available soups. In conclusion, D. maximum is nutritious enough to be popularized for domestication, wide consumption and inclusion in the form of instant food products in existing food basket.

Physiological and genomic evidence supports the role of Serratia quinivorans PKL:12 as a biopriming agent for the biohardening of micropropagated Picrorhiza kurroa plantlets in cold regions.

The medicinal herb, Picrorhiza kurroa Royle ex Benth has become endangered because of indiscriminate over-harvesting. Although micropropagation has been attempted for mass propagation of the plant, survival of in vitro plantlets under green house/open field poses a major challenge. Biopriming of micropropagated plantlets with plant growth-promoting rhizobacteria (PGPR) are among the successful methods to combat this problem. Serratia quinivorans PKL:12 was the best-characterized PGPR from rhizospheric soil of P. kurroa as it increased the vegetative growth and survival of the micropropagated plantlets most effectively. Complete genome (5.29 Mb) predicted genes encoding proteins for cold adaptation and plant growth-promoting traits in PKL:12. Antibiotic and biosynthetic gene cluster prediction supported PKL:12 as a potential biocontrol agent. Comparative genomics revealed 226 unique genes with few genes associated with plant growth-promoting potential. Physiological and genomic evidence supports S. quinivorans PKL:12 as a potential agent for bio-hardening of micropropagated P. kurroa plantlets in cold regions.

De novo transcriptome analysis of the critically endangered alpine Himalayan herb Nardostachys jatamansi reveals the biosynthesis pathway genes of tissue-specific secondary metabolites.

The study is the first report on de novo transcriptome analysis of Nardostachys jatamansi, a critically endangered medicinal plant of alpine Himalayas. Illumina GAIIx sequencing of plants collected during end of vegetative growth (August) yielded 48,411 unigenes. 74.45% of these were annotated using UNIPROT. GO enrichment analysis, KEGG pathways and PPI network indicated simultaneous utilization of leaf photosynthates for flowering, rhizome fortification, stress response and tissue-specific secondary metabolites biosynthesis. Among the secondary metabolite biosynthesis genes, terpenoids were predominant. UPLC-PDA analysis of in vitro plants revealed temperature-dependent, tissue-specific differential distribution of various phenolics. Thus, as compared to 25 °C, the phenolic contents of both leaves (gallic acid and rutin) and roots (p-coumaric acid and cinnamic acid) were higher at 15 °C. These phenolics accounted for the therapeutic properties reported in the plant. In qRT-PCR of in vitro plants, secondary metabolite biosynthesis pathway genes showed higher expression at 15 °C and 14 h/10 h photoperiod (conditions representing end of vegetative growth period). This provided cues for in vitro modulation of identified secondary metabolites. Such modulation of secondary metabolites in in vitro systems can eliminate the need for uprooting N. jatamansi from wild. Hence, the study is a step towards effective conservation of the plant.

Nardostachys jatamansi (D.Don) DC.-Challenges and opportunities of harnessing the untapped medicinal plant from the Himalayas.

ETHNOPHARMACOLOGICAL RELEVANCE: Nardostachys jatamansi (D.Don) DC. (family Caprifoliaceae) is prized in the Chinese, Tibetan, Nepalese, Bhutanese, Indian and Japanese systems of medicine. Its medicinal properties are well documented in ancient literature such as the Ayurvedic classics, the Old Testament, Ben-Cao- Shi-Yi, and Homer's Iliad. The plant is critically endangered and found in the alpine and sub-alpine regions of the Himalayas. AIM OF THE STUDY: Our study aims to show the challenges and opportunities of harnessing the untapped pharmaceutical resources of N. jatamansi. Another aim is to explore the possibilities of translating ethnobotanical information into health benefit applications. MATERIALS AND METHODS: The sources of information used in the study are government reports, dissertations, books, research articles and databases like Science-Direct, SciFinder, Web of Science, PubMed, Wiley Online Library, and ACS Publications on N. jatamansi. RESULTS AND DISCUSSION: In the study, we have examined and discussed reports on phytochemicals present in the plant, their structure, biological activity, pharmacological properties of extracts derived from plant parts, isolated compounds, and commercially available products from the plant. We have identified and discussed ambiguities and confusions about the plant's nomenclature and geographical distribution, and highlighted various studies that failed to discuss this issue. We analyzed the links between various reports on ethnobotanical information as well as studies on phytochemistry and pharmacologyconfirming the therapeutic properties of N. jatamansi. However, in many of these findings which had used dried samples, there was an uncanny resemblance between the phytochemical profiles and biological activities of N. jatamansi and Valeriana jatamansi Jones ex Roxb. (another genus from family, Caprifoliaceae). Since both the species share identical vernacular names, a possible reason could be that the samples may not have been of two separate species. Other limitations of different studies were the use of out-dated techniques for phytochemical profiling, absence of toxicology studies using animal models and clinical trials using human subjects. CONCLUSIONS: Analysis of various studies revealed a confusion about the botanical nomenclature of the plants and their geographical distributions. Absence of proper markers for identification of correct samples and improperly conducted studies on N. jatamansi were found to be the major hurdles to the use of ethnobotanical information and research findings into applications for human health. Development of markers using molecular, chemical and pharmacognosy based approaches for plant authentication and, in vitro propagation of authenticated material for easy availability of genuine plant material are the possible solutions to the problems identified.

De novo transcriptome provides insights into the growth behaviour and resveratrol and trans-stilbenes biosynthesis in Dactylorhiza hatagirea - An endangered alpine terrestrial orchid of western Himalaya.

This is the first report on de novo transcriptome of Dactylorhiza hatagirea, a critically-endangered, terrestrial orchid of alpine Himalayas. The plant is acclaimed for medicinal properties but little is known about its secondary-metabolites profile or cues regulating their biosynthesis. De novo transcriptome analysis was therefore, undertaken to gain basic understanding on these aspects, while circumventing the acute limitation of plant material availability. 65,384 transcripts and finally, 37,371 unigenes were assembled de novo from a total of 236 million reads obtained from shoot, tuber and leaves of the plant. Dominance of differentially-expressing-genes (DEGs) related to cold-stress-response and plant-hormone-signal-transduction; and those involved in photosynthesis, sugar-metabolism and secondary-metabolite-synthesis provided insights into carbohydrate-partitioning in the plant during its preparation for freezing winter at natural habitat. DEGs of glucomannan, ascorbic acid, carotenoids, phylloquinone/naphthoquinones, indole alkaloids, resveratrol and stilbene biosynthesis revealed the secondary-metabolite profile of D. hatagirea. UHPLC results confirmed appreciable amounts of resveratrol and trans-stilbene in D. hatagirea tubers, for the first time. Expression analysis of 15 selected genes including those of phenylpropanoid pathway confirmed the validity of RNA-seq data. Opportunistic growth, temperature- and tissue-specific-differential-expression of secondary metabolite biosynthesis and stress tolerant genes were confirmed using clonal plants growing at 8, 15 and 25 °C.

Proteome Analysis of the Gametophytes of a Western Himalayan Fern Diplazium maximum Reveals Their Adaptive Responses to Changes in Their Micro-Environment.

Ferns have survived changing habitats and environmental extremes of different eras, wherein, the exploratory haploid gametophytes are believed to have played a major role. Therefore, the proteome of in vitro grown gametophytes of a temperate Himalayan fern, Diplazium maximum in response to 0 (G0), 1 (G1), and 3% (G3) sucrose was studied. A total of 110 differentially abundant protein spots (DAPs) were obtained. Among these, only 67 could be functionally categorized as unique proteins involved in various metabolic processes. Calcium dependent proteins, receptor like kinases, G proteins, proteins related to hormonal signaling and their interaction with other pathways, and regulatory proteins were recorded indicating the involvement of five different signaling pathways. DAPs involved in the activation of genes and transcription factors of signaling and transduction pathways, transport and ion channels, cell-wall and structural proteins, defense, chaperons, energy metabolism, protein synthesis, modification, and turnover were identified. The gametophytes responded to changes in their micro-environment. There was also significant increase in prothallus biomass and conversion of two-dimensional prothalli into three-dimensional prothallus clumps at 3% sucrose. The three-D clumps had higher photosynthetic surface area and also closer proximity for sexual reproduction and sporophyte formation. Highest accumulation of proline, enhanced scavenging of reactive oxygen species (ROS) and DAPs of mostly, abiotic stress tolerance, secondary metabolite synthesis, and detoxification at 3% sucrose indicated an adaptive response of gametophytes. Protein Protein Interaction network and Principal Component analyses, and qRT-PCR validation of genes encoding 12 proteins of various metabolic processes indicated differential adjustment of gametophytes to different levels of sucrose in the culture medium. Therefore, a hypothetical mechanism was proposed to show that even slight changes in the micro-environment of D. maximum gametophytes triggered multiple mechanisms of adaptation. Many DAPs identified in the study have potential use in crop improvement and metabolic engineering programs, phytoremediation and environmental protection.

In vitro flowering associated protein changes in Dendrocalamus hamiltonii.

In Dendrocalamus hamiltonii, conversion of vegetative meristem to a floral meristem was successfully achieved on flower induction medium. A total of 128 differentially expressed proteins were evidenced by 2DE in floral meristem protein profiles. Analysis of 103 proteins through PMF revealed change in abundance in the content of 79 proteins, disappearance and new appearance in the content of 7 and 17 proteins, respectively. MS/MS and subsequent homology search identified 65 proteins that were involved in metabolism (22 proteins), regulatory (11 proteins), signaling and transportation (12 proteins), stress (6 proteins), flowering (8 proteins), and unknown functions (6 proteins). The data suggested that change in metabolism related proteins might be providing nutrient resources for floral initiation in D. hamiltonii. Further, interactive effects of various proteins like bHLH145, B-4c transcription factors (heat stress transcription factor), maturase K, MADS box, zinc finger proteins, and scarecrow-like protein 21 (flowering related), a key enzyme of ethylene biosynthesis SAMS (S-adenosylmethionine synthase) and aminocyclopropane-1-carboxylate synthase, improved calcium signaling related proteins (CML36), and change in phytohormone related proteins such as phosphatase proteins (2c3 and 2c55), which are the positive regulators of gibberellic acid and phytochrome regulation related proteins (DASH, LWD1) might be the possible major regulators of floral transition in this bamboo.

A simple technique for tracking individual spore and gametophyte development in Adiantum lunulatum Burm. f. using modified extra thin alginate film technique.

A new technique was developed for accurate calculation of percent germination and tracking of individual spores from germination to gametophyte development in Adiantum lunulatum. High percentage of ETAF immobilized spore germination (72.4%) was followed by development of gametophytic clumps. The ETAF immobilized clumps were cut into pieces and multiplied en masse. Apomictic sporophytes developed from the gametophytes. This indicated the potential of ETAF for mass propagation of A. lunulatum without the need to start from spores. Since individual spores can be tracked from germination to gametophyte development, the ETAF technique has the potential to be used for (i) harvesting uniformly developed plants of similar age for extensive experimentations and commercial utilization and (ii) detailed study on developmental and reproductive biology of different ferns and fern allies.

In vitro flowering--a system for tracking floral organ development in Dendrocalamus hamiltonii Nees et Arn. ex Munro.

Dendrocalamus hamiltonii plants are slender and tall (15-25 m) thereby, rendering tagging, sampling and tracking the development of flowers difficult. Therefore, a reproducible system of in vitro flowering was established for tracking the stages of flower development. MS medium supplemented with 2.22 microM 6-benzylaminopurine, 1.23 microM indole-3-butyric acid and 2% sucrose was optimized as the flower induction medium (FIM) wherein 28 and 42 days were required for the development of gynoecium and androecium, respectively. Six distinct stages of in vitro flower development were identified, and the flowers were comparable with that of in planta sporadic flowers. Pollen viability of the in vitro flowers was higher than those of in planta ones. The in vitro system developed in the present study facilitates easy tracking of different stages of flower development under controlled environmental conditions. It can also be used for medium- or long-term storage of pollens and manipulation of in vitro fertilization.

A simple and cost effective liquid culture system for the micropropagation of two commercially important apple rootstocks.

The two commercially important apple rootstocks i.e., MM106 and B9 were micropropagated using a liquid culture system. Three different strengths of 0.8% agar solidified PGR free basal MS medium were first tested to optimize the culture media for both the rootstocks. Full strength medium (MS0) supported maximum in vitro growth, multiplication, rooting and survival under field conditions as opposed to quarter and half strength media. When three different volumes of liquid MS0 were tested, highest in vitro growth, multiplication, rooting and also survival under field conditions were achieved in 20 mL liquid MS0. The cost of one litre of liquid medium was also reduced by 8 times to Rs. 6.29 as compared to solid medium. The cost of 20 mL medium was further reduced to Rs. 0.125.

Osmotin-expressing transgenic tea plants have improved stress tolerance and are of higher quality.

Drought is a major stress that affects the yield and quality of tea, a widely consumed beverage crop grown in more than 20 countries of the world. Therefore, osmotin gene-expressing transgenic tea plants produced using earlier optimized conditions were evaluated for their tolerance of drought stress and their quality. Improved tolerance of polyethylene glycol-induced water stress and faster recovery from stress were evident in transgenic lines compared with the normal phenotype. Significant improvements in growth under in-vitro conditions were also observed. Besides enhanced reactive oxygen species-scavenging enzyme activity, the transgenic lines contained significantly higher levels of flavan-3-ols and caffeine, key compounds that govern quality and commercial yield of the beverage. The selected transgenic lines have the potential to meet the demands of the tea industry for stress-tolerant plants with higher yield and quality. These traits of the transgenic lines can be effectively maintained for generations because tea is commercially cultivated through vegetative propagation only.

L-glutamine and L-glutamic acid facilitate successful agrobacterium infection of recalcitrant tea cultivars.

The first step in Agrobacterium tumefaciens infection of plants is the establishment of cell-cell contact between the two partners. However, failure to establish such contact makes many plants and explants recalcitrant to A. tumefaciens infection. Tea is one such example where even the popular inducer, acetosyringone failed to facilitate A. tumefaciens infection due to the presence of high amounts of bactericidal/bacteriostatic polyphenols. Quinones are formed as a result of polyphenols oxidation. They cause tissue browning and necrosis during the process of transformation, and in turn prevent A. tumefaciens infection. Compounds such as polyphenol adsorbents, i.e., polyvinylpyrrolidone and charcoal, and antioxidants like cysteine and ascorbic acid were screened to overcome tissue browning. Although these compounds enhanced the growth of A. tumefaciens, these failed to facilitate the infection of the leaves of either Kangra Jat, Tocklai Variety-1, UPASI-9, UPASI-10, and Stock-449 cultivars of tea. On the contrary, the presence of filter sterilized L-glutamine and L-glutamic acid in the co-cultivation medium facilitated successful A. tumefaciens infection of recalcitrant tea leaves. L-Glutamine and glutamic acid form harmless adducts by binding to quinones. Therefore, their presence in the co-cultivation medium allowed the tea leaves to remain living and appealing to the infecting A. tumefaciens. Successful A. tumefaciens infection of tea leaves was confirmed by positive signals in GUS assay, PCR, and Dot blot.

Factors affecting podophyllotoxin yield in the ex situ grown Podophyllum hexandrum, an endangered alpine native of the western Himalayas.

This study reports an appreciable yield of podophyllotoxin (PDT) in P. hexandrum plants grown ex situ under polyhouse conditions of a temperate locale. The PDT content of below-ground parts was affected by both plant age and growth period. However, only the effect of plant age on PDT content was significant. Thus, the highest amounts of PDT were recorded in the below-ground parts of 2-year-old plants harvested during the late-growth period (LGP). High total soluble sugars in the below-ground parts during the early growth period (EGP) and the highest nitrate and nitrate reductase in the leaves of 2-year-old plants during the peak-growth period (PGP) indicated higher mobilization and assimilation of starch and nitrate. Probably the surplus carbon and nitrogen gained during the PGP were diverted from aerial parts to below-ground parts during the LGP and in turn contributed to the synthesis of higher amounts of PDT. This study shows that commercial cultivation of P. hexandrum is possible under ex situ temperate conditions.

Chemical modification of L-glutamine to alpha-amino glutarimide on autoclaving facilitates Agrobacterium infection of host and non-host plants: A new use of a known compound.

BACKGROUND: Accidental autoclaving of L-glutamine was found to facilitate the Agrobacterium infection of a non host plant like tea in an earlier study. In the present communication, we elucidate the structural changes in L-glutamine due to autoclaving and also confirm the role of heat transformed L-glutamine in Agrobacterium mediated genetic transformation of host/non host plants. RESULTS: When autoclaved at 121°C and 15 psi for 20 or 40 min, L-glutamine was structurally modified into 5-oxo proline and 3-amino glutarimide (α-amino glutarimide), respectively. Of the two autoclaved products, only α-amino glutarimide facilitated Agrobacterium infection of a number of resistant to susceptible plants. However, the compound did not have any vir gene inducing property. CONCLUSIONS: We report a one pot autoclave process for the synthesis of 5-oxo proline and α-amino glutarimide from L-glutamine. Xenobiotic detoxifying property of α-amino glutarimide is also proposed.

The roles of plant phenolics in defence and communication during Agrobacterium and Rhizobium infection.

Phenolics are aromatic benzene ring compounds with one or more hydroxyl groups produced by plants mainly for protection against stress. The functions of phenolic compounds in plant physiology and interactions with biotic and abiotic environments are difficult to overestimate. Phenolics play important roles in plant development, particularly in lignin and pigment biosynthesis. They also provide structural integrity and scaffolding support to plants. Importantly, phenolic phytoalexins, secreted by wounded or otherwise perturbed plants, repel or kill many microorganisms, and some pathogens can counteract or nullify these defences or even subvert them to their own advantage. In this review, we discuss the roles of phenolics in the interactions of plants with Agrobacterium and Rhizobium.

An efficient method of propagation of Podophyllum hexandrum: an endangered medicinal plant of the Western Himalayas under ex situ conditions.

This study shows an effective but simple method of conserving characterized populations and elite clones through vegetative propagation and genetic diversity through seeds in Podophyllum hexandrum (family Berberidaceae). Seed dormancy has been considered to be a major constraint in these seeds and most of the earlier reports recommended dormancy-breaking pretreatments such as chilling, gibberellic acid (GA(3)), etc. However, seeds of the 14 accessions that we tested exhibited no dormancy and hence did not require any pretreatments. Besides accession, collection of seeds with high moisture content could be one of the reasons for lack of dormancy. Thus, we propose germination of seeds (while they still retained moisture) in sand at 25 degrees C for high and reproducible results within a shorter period of time compared with earlier reports. Hypocotyl dormancy is known to considerably delay plant establishment and hence en masse propagation by preventing the emergence of functional leaves for up to 11-12 months. Manual removal of cotyledonary leaves, being labor and time intensive, is not a feasible method for large-scale seedling establishment. However, in this study, we showed that GA(3) at 200 ppm can alleviate hypocotyl dormancy besides reducing the time taken for true or functional leaf emergence. Treatment of cotyledonary leaves of 1 week-old-seedlings with 200 ppm GA(3 )resulted in true or functional leaf emergence within 7 days, and the resultant plants were also more vigorous than the ones obtained from manual removal of cotyledonary leaves. The study helped advance the establishment of seedlings by one growing season (almost 1 year).

Temperature-dependent growth and emergence of functional leaves: an adaptive mechanism in the seedlings of the western Himalayan plant Podophyllum hexandrum.

As an adaptive mechanism, hypocotyl dormancy delays emergence of functional leaf until favorable season of growth in Podophyllum hexandrum, an endangered medicinal plant of the western Himalayas. However, upon exposure of the freshly germinated seedlings to favorable temperature (25 degrees C), functional leaves emerged within 20 days. Therefore, we examined regulation mechanisms of growth and development of this alpine plant by temperature under laboratory conditions. The seedlings were exposed to (1) 25 degrees C (temperature prevailing at the time of maximum vegetative growth), (2) 4 degrees C (mean temperature at the onset of winter in its natural habitat), and (3) 10 degrees C (an intermediate temperature). Slackened growth at 4 degrees C was followed by senescence of aerial parts and quiescence of roots and predetermined leaf primordia. Rapid development of leaf primordia at 25 degrees C was associated with increased starch hydrolysis. This was evident from higher alpha-amylase activity and reducing sugars. These parameters decreased on sudden exposure to 4 degrees C. In contrast, the roots (perennating organs) showed a slight increase (1.36-fold) in alpha-amylase activity. Growth and development in seedlings growing at 10 degrees C (temperature less adverse than 4 degrees C) were comparatively faster. The content of reducing sugars and alpha-amylase activity were also higher in all the seedling parts at 10 degrees C as compared to 4 degrees C. This indicated larger requirements for sugar by the seedlings at 10 degrees C. Irrespective of temperature, maximum changes in nitrate and nitrate reductase occurred during the initial 10 days, i.e., when the readily available form of sugars (reducing sugar) was highest. This indicated that a temperature-dependent availability of carbon, but not temperature itself, was an important regulator of uptake and reduction of nitrogen.

Agrobacterium-mediated genetic transformation of tea leaf explants: effects of counteracting bactericidity of leaf polyphenols without loss of bacterial virulence.

Tea is one of the major crops in Asia and Africa, and its improvement by genetic modification is important for economy of many tea-producing regions. Although somatic embryos derived from cotyledon explants have been transformed with Agrobacterium, the leaves of several commercially important tea cultivars have remained recalcitrant to transformation, largely due to bactericidal effect of polyphenols that are exuded by tea leaves in vitro. Moreover, the commonly used polyphenol adsorbents and antioxidants cannot overcome this problem. Leaf explants, however, are more desirable than cotyledon-derived somatic embryos, especially when it is necessary to further improve a selected elite and also retain its superior traits. Thus, we developed a procedure for Agrobacterium-mediated genetic transformation of tea leaf explants which is based on the presence of L-glutamine in the co-cultivation medium. We then showed that the transformation process is facilitated via a protective action of L-glutamine against bactericidal effects of leaf polyphenols without affecting the bacterial virulence (vir) gene expression.

ABA associated biochemical changes during somatic embryo development in Camellia sinensis (L.) O. Kuntze.

The effect of ABA on reserve accumulation in maturing somatic embryos of tea was compared with and without ABA treatment. Changes in the levels of starch, total soluble sugars (TSS), proteins, and phenols were studied in the somatic embryos at different stages of development (globular, heart, torpedo and germinating embryos) in order to investigate whether ABA could trigger accumulation of storage reserves and thereby overcome the problem of poor germination. After ABA treatment (5.0 mg l(-1)) for 14 days, the starch and protein contents that were negligible in the untreated embryos increased by several fold with a simultaneous increase in TSS. When ABA treatment occurred at the heart stage, the germination of the embryos also improved, relative to untreated controls, after ABA treatment. ABA treatment prior to or after heart stage did not improve somatic embryo germination.

Do leaf surface characteristics affect Agrobacterium infection in tea [Camellia sinensis (L.) O Kuntze]?

The host range specificity of Agrobacterium with five tea cultivars and an unrelated species (Artemisia parviflora) having extreme surface characteristics was evaluated in the present study. The degree of Agrobacterium infection in the five cultivars of tea was affected by leaf wetness, micro-morphology and surface chemistry. Wettable leaf surfaces of TV1, Upasi-9 and Kangra jat showed higher rate (75%) of Agrobacterium infection compared to Upasi-10 and ST-449, whereas non-wettable leaves of A. parviflora showed minimum (25%) infection. This indicated that the leaves with glabrous surface having lower q (larger surface area covered by water droplet), higher phenol and wax content were more suitable for Agrobacterium infection. Caffeine fraction of tea promoted Agrobacterium infection even in leaves poor in wax (Upasi-10), whereas caffeine-free wax inhibited both Agrobacterium growth and infection. Thus, study suggests the importance of leaf surface features in influencing the Agrobacterium infection in tea leaf explants. Our study also provides a basis for the screening of a clone/cultivar of a particular species most suitable for Agrobacterium infection the first step in Agrobacterium-mediated genetic transformation.