Compound inflorescence cardamom (Elettaria cardamomum (L.) Maton) in India

Cardamom (Elettaria cardamomum (L.) Maton) is an important spice crop of India and valued for its dried capsules. Regular surveys are being undertaken by Indian Institute of Spices Research (IISR), Appangala, Karnataka, India for collecting the variable germplasm of cardamom. At present 436 cardamom accessions collected from cardamom growing tracts of South India are conserved in field gene bank. Among the collections, 23 accessions with varied branching pattern were assembled during explorations and characterized for 16 plant, panicle and capsule characters during 2003–2005. The coefficient of variation was greatest for yield per plant (77.94%) followed by branches per panicle (49.40%) and minimum for dry recovery per cent (7.73%). Two accessions, IC 547214 and IC 349544 were identified as promising with desirable yield contributing characters. The accessions, IC 349553 with extensive branching at the proximal end of the panicle and IC 547180 with dark green capsules even after drying were found to be unique. All the characterized accessions are maintained under ex situ cardamom gene bank of IISR.     

Characterization of core collection of lentil germplasm for phenology, morphology, seed and straw yields

Increasing and maintaining crop residues in predominantly cereal-based rotations of the US Pacific Northwest is critical to controlling soil erosion. The core collection of lentil (Lens culinaris Medik.) germplasm comprising 287 accessions was evaluated for variation in phenological, morphological and growth parameters including seed yields and residue amounts over a two-year period under conventional tillage and no-till conditions. The objectives of this study were (i) assess lentil genetic variation in germplasm for variation in biomass production and seed yield, (ii) assess the relationship of phenological and morphological traits with biomass and seed yield and (iii) identify high biomass producing germplasm for use as parents in the breeding program. Days to flowering and days to maturity ranged from 31 to 78 and from 71 to 106 days, respectively. Time to flowering in terms of cumulative heat units was a more efficient measurement than days to flowering. Plant height and plant canopy width had a significant association with total biomass, seed yield and residue amounts. Total biomass ranged from 788–6389 kg ha^–1 under conventional tillage, while the range under no-till conditions was 1045–6195 kg ha^–1. Most of the lines with higher biomass also produced the highest seed yields and residue amounts. Overall, only one accession produced more residue than `Laird'. In the more favorable environment of 1997, six accessions exceeded the control cultivars, `Laird' and `Indianhead', for residue amounts, and seven and twenty-four accessions exceeded control cultivars, `Pardina' and `Brewer', for seed yield. Results indicated that plant height, canopy width at maturity and seed yield explained most of the variation in biomass and residue production. Large seeded germplasm consistently had a longer reproductive growth period than small seeded accessions and had 17%, 7% and 21% more biomass, seed yield and residue, respectively. Our data indicated significant variation in lentil germplasm for biomass, seed yield and residue amounts to warrant their use in the breeding program.     

Nitrogen fixation,biomass production,and nutrient uptake by annual Sesbania species in an alkaline soil

Summary In three field trials conducted during the summer season of 1986, 1987 and 1989 in an alkaline soil, 17 accessions of annual Sesbania spp. were evaluated for nodulation, N₂ fixation (acetylene reduction assay), dry weight of roots and shoots, woody biomass production, and nutrient uptake. At 50 days after sowing all the accessions were effectively nodulated (average 36.4 root nodules plant^-1) with a high nodule score (3.4). There was a lot of variation in nodule volume and mass and in acetylene reduction activity but not in N content (5.2%). N uptake in shoots, roots and nodules averaged 639, 31, and 13 mg plant^-1, respectively, and much of the fixed N remained in shoots. Accessions of S. cannabina complex performed better than others. S. rostrata had poor root nodulation but exhibited excellent stem nodulation (300 nodules plant^-1) even though not inoculated with Azorhizobium sp. Average concentrations of N, P, K, S, Ca, and Mg in the shoots were high, at 3.2, 0.28, 1.5, 0.28, 1.5, and 0.4% respectively, and Na was low (0.15%), reflecting the usefulness of Sesbania spp. as an integrated biofertilizer source. Green matter production was 26.0 Mg ha^-1 (5.9 Mg dry matter) and N uptake was 158 kg ha^-1, 54 days after sowing. Average woody biomass of six accessions at maturity, 200 days after sowing, was high (19.9 Mg ha^-1), showing its potential for shortterm firewood production. Total nutrient uptake for production of woody biomass (200 days of growth) was no more demanding than growing the plant to the green-manuring stage of 50–60 days' growth.     

Pattern of diversity for morphological and alkaloid yield related traits among the periwinkle Catharanthus roseus accessions collected from in and around Indian subcontinent

Thirty two accessions of periwinkle Catharanthus roseus collected from different semitemperate to tropical geographical areas of Indian subcontinent, Madagascar, Singapore and Malaysia were characterized under field conditions for 53 growth, development, morphogenesis and alkaloid yield related characters over a few seasons at Lucknow, India. Large differences were observed among the accessions for each of the characters examined. The differences among the accessions ranged 3, 80 and 15 fold for the alkaloid yield related traits – leaf dry matter yield and leaf vincristine and vinblastine concentration, respectively. Strong correlations were observed between leaf area and leaf yield with leaf alkaloid, root and root alkaloid yields, contents of dimeric alkaloid in leaves with yields of respective alkaloids, leaf number and root alkaloid content with leaf vinblastine yield and leaf vinblastine content with leaf vincristine and vinblastine yields. Multi-variate analyses allowed classification of the accessions into 5 to 7 morphologically and presumably genetically distinct groups. Generally, the accessions coming from tropical agro-climates tended to get separated from those having origins in subtropical to semi-temperate environments. Three clusters were observed to bear complementary characters for possibly cross-parenting high alkaloid yielding transgressive segregants. One of the accessions of C. roseus in which the leaf vincristine content was 5 fold and vinblastine content one and a half fold of the respective all accession means appeared suitable for the domesticated cultivation. It was proposed that accumulation of high amounts of total alkaloids and one or more dimeric alkaloids in leaves of certain accessions may be a reflection of reproductive fitness achieved under the biotic and abiotic stresses imposed on their parent populations, sometime in their evolutionary pathway.     

Evaluation of Wild Lens Taxa for Agro-Morphological Traits, Fungal Diseases and Moisture Stress in North Western Indian Hills

Exploitation of wild gene pool for breeding is a common practice in an increasing number of cultivated plants. The cultivated lentil could not attain the substantial improvement in the yield potential due to loss of genes for higher productivity and lack of resistance against biotic and abiotic stresses. The absence of evaluation data of wild lentils for characters of economic importance, besides biotic and abiotic stresses, is one of the constraints in their use in lentil breeding programme. In the present study, 70 wild accessions from four wild Lens subsp./sp. (L. culinaris subsp. orientalis, L. odomensis, L. ervoides and L. nigricans) along with 3 checks (Precoz, PL-406 and PL-639) were evaluated for phenological and agro-morphological characters, for their reaction to three fungal diseases (wilt, powdery mildew and rust) and screened for tolerance to moisture stress. The wild accessions showed higher performance for branches/plant as compared to cultivated genotypes. Similarly, a few accessions of L. culinaris subsp. orientalis were earlier to flower and had higher seeds and seed yield/plant as compared to cultivated lentil. However, some were comparable with cultivated genotypes for flowers/peduncle, peduncle length and plant height. The mean performance for flowers per peduncle, leaflets per leaf, plant height, seeds and seed yield per plant increased, while decreased for days to flowering and maturity, and branches per plant during the evolution of cultivated lentil from the wild Lens taxa. Of Lens taxa, L. nigricans had the maximum resistant accessions for biotic and tolerance to abiotic stresses. The valuable variation existing among wild accessions can be exploited following introgression with cultivated lentils. It will help in the flow of useful genes from wild to cultivated lentil for generating wide spectrum of variability and its subsequent use in genetic restructuring of lentil.     

Changes in seed Morphology, Dormancy and Germination from wild to Cultivated Hyacinth bean Germplasm (Lablab purpureus: Papilionoideae)

Morphological and physiological seed characteristics of the hyacinth bean (Lablab purpureus) were investigated in a set of 18 different germplasm accessions, from wild over semi-domesticated forms to landraces and current cultivars. The objective of this study was to improve the understanding of the domestication of this tropical legume crop. Wild accessions were easily distinguished by morphological characters, such as small, greyish-brown, mottled seeds. Cultivated or semi-domesticated forms showed a much wider variation in size, colour and shape. Seed mass of cultivated accessions reached up to almost 10 times that of wild accessions. Most wild accessions showed a greater spread of germination and larger proportions of hard seeds, up to about 70%, than most cultivated and so-called semi-domesticated accessions. Cluster analysis applied separately to morphological and germination data and a subsequent discriminant analysis did not help integrating the morphological variability observed. The presumed occurrence of semi-domesticated accessions within the germplasm tested as well as the crop's origin from Africa alone or both Africa and Asia are debated on the basis of seed germination and hard seed coat dormancy.     

Variability in Mucuna pruriens L. germplasm for L-Dopa, an anti parkinsonian agent

Mucuna pruriens L. (Fabaceae) is a popular Indian medicinal plant, which has long been used in traditional Ayurvedic system of Indian medicine for diseases including parkinsonism. The seeds of M. pruriens contain 3,4-dihydroxyphenyl-L-alanine (L-dopa) as a major constituent, an intermediate precursor of the neurotransmitter dopamine. L-dopa extracted from seeds of Mucuna is more effective as drug than the synthetic counterpart. The plant is widely distributed throughout the India and in other parts of the tropics including Central and South America. The present study was aimed to screen thirty-eight accessions of Mucuna germplasm collected from different geographical regions of India for L-dopa content, an effective drug used for Parkinson’s disease. The L-dopa content in seeds of M. pruriens was quantitatively analyzed by high performance thin-layer chromatography (HPTLC) at 280?nm wavelength. Results indicated wide variability among thirty-eight accessions of M. pruriens for seed characters like seed colour, size and shape. The L-dopa content in seeds of M. pruriens ranged between 3.29 and 5.44?% (on dry weight basis) among different germplasm collections augmented from various parts of India. Promising accessions identified having high L-dopa content were IC551549 (5.44?%), IC551514 (5.41?%), IC331536 (5.40?%), IC552857 (5.36?%), IC385844 (5.32?%) and IC439197 (5.32?%). Due to the economic importance of the drug, these promising M. pruriens accessions can be exploited for large scale cultivation for their pharmacological important constituents mainly L-dopa content.     

Variation of cultivated flax (Linum usitatissimum L. subsp.usitatissimum) and its wild progenitor pale flax (subsp.angustifolium (Huds.) Thell.)

The domestication of cultivated flax (Linum usitatissimum L. subsp.usitatissimum) is briefly discussed. Using data documented as a matter of routine in genebank work, 63 accessions of cultivated flax from the flax germplasm collection of the Gatersleben Genebank are compared with 73 accessions of its wild progenitor pale flax (subsp.angustifolium (Huds.) Thell.), which have been observed in systematic field trials. Range of variation, genetically based variation, heritability and correlation of several characters are considered, especially with respect to the influence of domestication. Cultivated flax shows higher variation in the characters of generative plant parts, while pale flax varies more in the vegetative parts of the plant. The character correlations are similar in both subspecies. Of the 29 characters studied in pale flax the parameters describing tillering, height of plant, weight of seeds, width of petals and width of leaves are especially suitable for distinguishing between different accessions. In spite of the high heritabilities of most of the characters, the influence of the environment is significant in most cases.     

Effect of Nitrogen Application Timing on Yield Components,Fodder, Grain,and Oil Yields of Brassica Cultivars

The dual-purpose use of Brassica cultivars means cutting or grazing the crop as fodder and then letting it to re-grow and produce grain with little or no yield penalty. A field experiment was conducted in randomized complete block design with split plot arrangement with three replications. Three Brassica cultivars, three nitrogen application timing, and cutting treatments were included in the experiment. The findings indicated that Brassica cultivar Abasin-95 produced higher fresh and dry fodder yields, seeds pod^?1, seed, biological, and oil yields. However, NIFA Raya resulted in a higher number of pods and branches plant^?1. Likewise, fresh and dry fodder yields were higher with nitrogen (N) application all at sowing. Nitrogen applied in two splits resulted in a higher number of pods plant^?1 and grain yield. Cutting suppressed all parameters except 1000 grain weight. Uncut plots produced significantly higher branches plant^?1, pods plant^?1, seeds pod^?1, seed, biological, and oil yields than cut plots.     

A sensitive method for measuring cyanide and cyanogenic glucosides in sand culture and soil

Summary Sensitive methods for measuring cyanide and cyanogenic glucosides in soil and sand culture have been developed. A microdiffusion technique is described which depends on the enzymic conversion of linamarin and lotaustralin to HCN, its release following acidification and incubation, and its detection in NaOH. Conditions for hydrolysis and HCN recovery have been optimised. The cyanide content of a silt loam soil (under non-cyanogenic wheat) was 5.47 nmol cyanide g^–1 air-dried soil whilst that in an organic soil under the cyanogenic bracken, Pteridium aqgilinum, was 12.2 nmol g^–1. Exudation of cyanogenic glucosides by linseed, Linum usitatissimum, was measured in plant growth tubes containing sand and a nutrient medium. Sterile plants exuded an average of 6.88 nmol glucosides plant^–1 week^–1 whilst, in contaminated tubes, the level fell to 4.72 nmol. Analysis of plant roots on each sampling occasion showed that 6.88 nmol was, on average, equivalent to 16.15% of the total root content of cyanogenic glucosides. There was a low but positive correlation between fresh weight of plant roots and the level of exuded glucosides. There was no evidence that plant roots produced free HCN.     

Biomass production and related characters in the core collection of Pisum germplasm

Retention of residue on the soil surface following harvest is an effective method of reducing soil erosion from both wind and water. The pea crop produces small amounts of residue to effectively reduce soil erosion. Severe erosion occurs in pea production areas such as the Palouse Region of the US Pacific Northwest (PNW) when low residue crops such as spring pea or lentil are followed by fall-sown wheat. The current study was conducted to determine the range of total aboveground biomass (TAB), seed yield, and straw (residue) production from the plant identification (PI) accessions that comprise the core collection of Pisum germplasm. In addition, the potential for increasing seed yield and straw production simultaneously was evaluated. Three hundred and ninety PI accessions were screened in the field in 1996 and 1997. The variation for TAB, seed yield and straw production among the PI accessions exceeded that of the controls both years. Seed yield was positively correlated with straw production (r = 0.81, p< 0.01) indicating that seed and straw production can be increased simultaneously through positive selection for both traits. Significant favorable variation is present among accessions in the USDA core collection of Pisum germplasm which could be used to increase both seed yield and total biomass production of adapted breeding lines.     

Patterns of diversity in pigeonpea (<Emphasis Type="Italic">Cajanus cajan</Emphasis> (L.) Millsp.) germplasm collected from different elevations in Kenya

Pigeonpea germplasm accessions collected from low (<500 m), medium (501–1000 m), high (1001–1500 m) and very high elevation zones (>1500 m) of Kenya were evaluated for 15 agronomic traits and seed protein content at ICRISAT, Patancheru, India. There were significant differences (P < 0.001) among elevation zones for the number of primary and secondary branches, days to 75% maturity, pod length, seeds per pod, 100-seed weight and seed yield. Mean values indicated that the accessions from low elevation zone were significantly different from those collected in higher elevation zones for early flowering and maturity, number of primary branches, pod length, number of pods per plant, seeds per pod, 100-seed weight, seed yield and harvest index. None of the accessions collected in Kenya belonged to extra early (<80 days to 50% flowering) and early (80–100 days to 50% flowering) maturity groups, as defined by time to flowering at Patancheru, India. Mean diversity index based on all characters indicated that accessions from the low elevation zone are more diverse than those from the higher elevation zones. Frequency distribution for trait extremes indicated that the accessions from the low elevation zone were early to flower and mature, short statured, produced more primary and secondary branches with high pod bearing length, long pods, more pods per plant, more seeds per pod, a high seed yield and harvest index. Accessions from the very high elevation zone were late flowering, with a large number of tertiary branches, large seeds and a high shelling percentage and could be a source for cold tolerance and the breeding of vegetable types. Results suggest that the elevation of collection sites is therefore a very important determinant of variation patterns of pigeonpea in Kenya.     

Sources of resistance to downy mildew in narbon (Vicia narbonensis) and common (Vicia sativa) vetches

Downy mildew (Peronospora viciae (Berk) de Bary) is an important disease of vetches (Vicia spp.) in the Mediterranean Region. Narbon and common vetch germplasm accessions originating from different countries, and advanced breeding narbon vetch genotypes, were evaluated for reaction to downy mildew for two seasons under field conditions. In narbon vetch, there were resistant sources from both germplasm accessions and advanced genotypes. From the germplasm accessions, 25 accessions were resistant while from the advanced breeding genotypes, 10 had resistance, with 2–3 ratings. In common vetch, many accessions were highly resistant to downy mildew. These were widely distributed in different countries, mainly Turkey, Italy, Syria and Iran. In general, common vetch had higher sources of resistance than the narbon vetch accessions. These new sources of resistance to downy mildew will be incorporated into the forage legume improvement project in a continuous effort to identify cultivars suitable for replacing fallow in the cereal-based cropping systems.     

Acetylene reduction,hydrogen evolution and nodule respiration in Phaseolus vulgaris

Summary In an experiment performed under greenhouse conditions, four cultivars of Phaseolus vulgaris L. (Venezuela-350; Aroana; Moruna; Carioca) were inoculated with three Rhizobium leguminosarum biovar phaseoli strains (C-05; C-40 = CIAT 255; C-89 = CIAT 55) and were fertilized with an N-free mineral nutrient solution. The plants were harvested 25, 40, and 55 days after emergence and the following paramenters were evaluated: Nitrogenase activity of nodulated roots, H₂ evolution by the nodules; relative efficiency of nitrogenase; respiration rates of nodulated roots and detached nodules; dry weight and total N of stems, leaves, pods, roots, and nodules. Generally the bean cultivar, Rhizobium strain, had an effect and there was an interaction effect with both symbiotic partners, on all parameters. On average, nodules represented 23% of total root respiration but the best symbiotic combinations showed lower ratios of C respired to N fixed. The maximum N-assimilation rate (between 40 and 55 days after emergence) of 11.93 mg N plant^–1 day^–1 occurred with the symbiotic combination of Carioca × C-05, while the poorest rate of 0.55 mg N plant^–1 day^–1 was recorded with Venezuela-350 × C-89. The best symbiotic combinations always showed the highest relative nitrogenase efficiency, but the differences in N₂-fixation rates cannot be explained solely in terms of conservation of energy by recycling of H₂. This requires further investigation.     

Collection of Lupinus angustifolius L. Germplasm and Characterisation of Morphological and Molecular Diversity

Lupinus angustifolius L. is a Mediterranean species, domesticated in the 20th century, representing an important grain legume crop in Australia and other countries. This work is focused on the collection of wild germplasm and on the characterisation of morphological and molecular diversity of germplasm accessions. It reports the collection of 81 wild L. angustifolius accessions from the South and Centre of Portugal, available at the ‘Instituto Superior de Agronomia Gene Bank’, with subsequent morphological and molecular characterisation of a selection of these and other accessions. A multivariate analysis of morphological traits on 88 L. angustifolius accessions (including 59 wild Portuguese accessions, 15 cultivars and 14 breeding lines) showed a cline of variation on wild germplasm, with plants from Southern Portugal characterised by earlier flowering, higher vegetative development and larger seeds. AFLP and ISSR molecular markers grouped modern cultivars as sub-clusters within the wider diversity of wild germplasm, revealing the narrow pool of genetic diversity on which domesticated accessions are based. The importance of preserving, characterising and using wild genetic resources for L. angustifolius crop improvement is outlined by the results obtained.     

Incidence and viability of Acremonium endophytes in tall fescue accessions from North Spain

The tall fescue (Festuca arundinacea Schreb.) seed collection of the Centro de Investigaciones Agrarias de Mabegondo was surveyed to determine Acremonium infection rates. One hundred seeds from each of 19 accessions were microscopically examined for endophyte. Seventeen accessions (90%) contained endophyte with a range of 7 to 100%. Leaf sheaths of seedlings from the infected accessions were examined to determine the percentage of infection with viable endophyte. Only seven (41%) of the seventeen infected accessions collected and stored in 1995 at 4°C and 45–50% relative humidity contained viable endophyte with a range of 70 to 100%. While existing germplasm collections of Festuca arundinacea can provide only a small basis of Acremonium germplasm for study, newly collected Festuca arundinacea accessions will offer a greater diversity of Acremonium genotypes.     

Alkaloid profiles of the Indian land races of the opiumpoppy Papaver somniferum L.

The capsule husks of a set of 115 Indian land races of opium poppy Papaver somniferum L. obtained over two cropping seasons were screened for the percent contents of papaverine, reticuline, narcotine, thebaine, codeinone, codeine,morphine and oripavine. Among the accessions screened 36, 7 and 1 didnot accumulate papaverine, papaverine and narcotine and codeine and morphine, respectively. The alkaloid profiles and correlations between alkaloids in all the four classes of accessions showed thatin the Indian genetic resources of P.somniferum (a) morphine is synthesized from codeine rather than oripavine, (b) net alkaloid contents are low under narcotine deficiency, and (c)accumulation of morphine and codeine was limited upstream of codeine and morphine. The accessions identified to be harboring genetic blocks in the phenenthrine and benzylisoquinolinebiosynthetic pathways will be useful for understanding the genetic control of secondary metabolism in opium poppy.     

Effect of soil treatment with cereal straw and method of crop establishment on field pea (Pisum sativum L.) N2 fixation

The effects of soil incorporation with cereal straw (nil, 2.5, 5 and 10 t straw ha^–1) and direct drilling on the proportion and amount of pea N derived from biological N fixation were investigated in three field experiments. Fixed N was determined by¹⁵N dilution using barley as a reference plant. The three sites were on acidic, red clay-loams in the cropping zone of southeastern Australia. Seasonal plant available soil N, as determined by the N accumulated in barley, was 31, 56 and 158 kg N ha^–1, for the three sites. Incorporated straw reduced soil nitrate at sowing by 10–50 kg N ha^–1 (0–30 cm), and 5 or 10 t straw ha^–1 reduced barley uptake of N by 10–38 kg N ha^–1. However, reducing plant available soil N was generally ineffective for increasing the N fixed by pea. Fixed N increased only at the site with the least plant-available N, and only one-third of the increase could be attributed to lower soil N uptake by pea. There was no evidence that direct drilling pea increased fixed N by decreasing crop uptake of soil N. It is proposed that a lower requirement for soil N by pea as compared to barley, and availability of mineral N beneath the soil layer treated with straw, minimise the effectiveness of straw incorporation for increasing the N fixed by pea.     

Alkaloid Spectrum of Different Germplasm Lines in Opium Poppy (Papaver somniferum L.)

The opium latex of 1470 individual plant samples of 98 germplasm lines were screened for five major economic alkaloids. The alkaloids profile showed that morphine content ranged from 9.20–20.86% with an average of 15.00 ± 0.267. Codeine ranged from 1.69–6.48% with arithmetic mean of 3.35 ± 0.091, thebaine from 0.52–7.95% with an average of 2.27 ± 0.116. Narcotine ranged from 8.79–17.97% with an average 8.79 ± 0.266 and papaverine content ranged from 0.00–6.07% with an average 1.18 ± 0.167 in over all the germplasm lines. The content of different alkaloids categorized into class interval which exhibited that maximum number of plants and accessions for morphine content fall in group of 10–15% followed by 15–20%, for codeine content in group of 2–4% followed by 4–6%, for thebaine content in 1–2% followed by 2–4%, for narcotine in 5–10% followed by 10–15% and for papaverine content 0–2%. 24 germplasm lines had morphine content above 16.0%. Similarly, 37 germplasm lines for codeine and 13 for thebaine showed consistently high content, i.e., above 3%. 33 germplasm lines had narcotine content above 9% and 20 lines exhibited papaverine content above 2%. Line BR 316 was found unique having thebaine content 6.27–9.33%. The probable reasons of increase or decrease of different alkaloids based on their biosynthetic pathway has been discussed in detail.