The Cuban homegarden ‘conuco’: a perspective environment for evolution and in situ conservation of plant genetic resources

Summary Cuban homegardens are called conucos. On the basis of new case studies additional information is provided about these conucos, their history, composition and importance. They and other gardens of similar type are characterized as suitable environment for in situ conservation and for the continuation of evolutionary processes.     

‘Neodomesticates’ of the Himalayan allium spices (Allium species) in Uttarakhand,India and studies on eco-geography and morphology

Genetic Resources and Crop Evolution - The study on Himalayan allium spices was undertaken with specific reference to commercially important taxa belonging to the genus Allium viz. A. stracheyi...     

POPs in Mountain Soils from the Alps and Andes: Suggestions for a ‘Precipitation Effect’ on Altitudinal Gradients

POPs are still a priority environmental problem, but can be used as a scientific tool for understanding the distribution phenomena. Both high mountains and polar areas are seen as priority zones for contamination studies. In this context, two altitudinal series of soil samples were analysed for several classes of Persistent Organic Pollutants (PCBs, DDTs, HCHs, HCB and chlordane). Two transects were carried out – one in the Peruvian Andes (Cordillera Blanca) and the other in the Italian Alps (Mount Legnone). In these two areas, POP composition and levels both gave different results, linked to regional emission history. The Italian samples were characterized by high levels of industrial type compounds, and by surprisingly high DDT contamination, due to a defined consistent local source in Northern Italy. The Peruvian samples, on the other hand, were characterized by generally low POP levels with relatively high DDT contamination. The concentration increase in line with elevation was evident only in the Italian transect, where higher precipitation intensities and an increasingly higher precipitation gradient in accordance with altitude was found present. Precipitations are considered a key factor for enhancing the condensation effect at high altitudes and for reducing summer revolatilisation, as they lower soil temperature. In the Italian altitudinal gradient, evidence of fractionation processes, with a shift of the PCB composition towards less chlorinated congeners, and a vegetation effect with a mean woodland/grassland enrichment factor between 2 and 4 were also observed.     

Bayesian Inference for Multistate ‘Step and Turn’ Animal Movement in Continuous Time

Mechanistic modelling of animal movement is often formulated in discrete time despite problems with scale invariance, such as handling irregularly timed observations. A natural solution is to formulate in continuous time, yet uptake of this has been slow. This lack of implementation is often excused by a difficulty in interpretation. Here we aim to bolster usage by developing a continuous-time model with interpretable parameters, similar to those of popular discrete-time models that use turning angles and step lengths. Movement is defined by a joint bearing and speed process, with parameters dependent on a continuous-time behavioural switching process, creating a flexible class of movement models. Methodology is presented for Markov chain Monte Carlo inference given irregular observations, involving augmenting observed locations with a reconstruction of the underlying movement process. This is applied to well-known GPS data from elk (Cervus elaphus), which have previously been modelled in discrete time. We demonstrate the interpretable nature of the continuous-time model, finding clear differences in behaviour over time and insights into short-term behaviour that could not have been obtained in discrete time.     

Genetic diversity in local cultivars of garden pea (Pisum sativum L.) conserved ‘on farm’ and in historical collections

During a national Swedish collection mission of vegetable varieties conserved ‘on farm’ more than 70 pea accessions were obtained, many of which had been grown locally for more than 100 years. In spite of a likely origin in the multitude of obsolete commercial pea varieties available on the Swedish seed market in the nineteenth century, the rediscovered local cultivars have lost their original names and cultivar identity while being maintained ‘on farm’. To analyze genetic diversity in the repatriated material, 20 accessions were genotyped with twelve SSR markers and compared with 15 obsolete cultivars kept in genebanks and 13 cultivars preserved as non-viable seeds collected in 1877–1918. Most of the local cultivars were genetically distinct from each other, and in only a few cases could a possible origin in a tested obsolete cultivar be suggested. These results reflect the wide diversity of pea cultivars present in Sweden during the nineteenth century. Both between and within accession genetic diversity was larger among the historical samples of obsolete cultivars compared to local cultivars and cultivars preserved in genebanks, indicating genetic erosion over time both in genebanks and during conservation ‘on farm’. The constraints on identifying and verifying historical cultivars using genetic markers are discussed.     

Habitat prediction mapping using BioClim model for prioritizing germplasm collection and conservation of an aquatic cash crop ‘makhana’ (Euryale ferox Salisb.) in India

An aquatic cash crop, ‘makhana’ (Euryale ferox Salisb.) was studied for predicted habitat suitability through ‘BioClim’ model for the year 1950–2000 and projected climate data for 2050 and 2070 for the Indian region based on primary data from survey and exploration for germplasm collection by ICAR-National Bureau of Plant Genetic Resources (ICAR-NBPGR), New Delhi, India. A total of 362 diverse ‘makhana’ or foxnut germplasm accessions were augmented mainly from different districts of Indian state of Bihar and conserved at the National Genebank (NGB) at ICAR-NBPGR, New Delhi. Predicted habitat suitability map of climate for the period 1950–2000 showed that the current locations of the highly suitable areas of cultivation of ‘makhana’ in Bihar were extended to other states namely- Jharkhand, Uttar Pradesh and West Bengal in eastern India. Out of the total highly suitable estimated areas, maximum were located in Bihar (65.0 per cent) followed by Uttar Pradesh (12.3 per cent), Jharkhand (12.2 per cent) and West Bengal (10.5 per cent). Based on future predicted climate data for the year 2050 the habitat suitability map indicated that out of the total high suitable areas, Bihar had maximum area as compared to the other three states. Predicted climate data using ‘BioClim’ variables showed that high suitable areas shifted from major part in Jharkhand, Uttar Pradesh and West Bengal and negligible areas bordering Katihar district of Bihar. While predicted climate data for the year 2050 and 2070 showed high suitable areas in West Bengal, especially Malda and Dakschin Dinajpur districts completely shrank due to temperature rise; while Uttar Dinajpur (Goal Pokhar-I, Goal Pokhar-II and Islampur districts) appeared as new areas. In Uttar Pradesh, new districts viz. Balrampur and Shravasti were identified as high suitable areas for ‘makhana’ cultivation. As ‘makhana’ is a popular cash crop of eastern part of the country, and has not been cultivated widely in other regions, hence the knowledge on its botany, distribution, cultivation practices and uses are provided.

     

Morphological variation among shea tree (Vitellaria paradoxa subsp. nilotica) ‘ethnovarieties’ in Uganda

Vitellaria paradoxa C. Gaertn. (shea butter tree) is an indigenous African tree species that is widely distributed in the dry areas of northern and eastern Uganda. The species is widely known for its oil which is used in cooking, cosmetics and traditional medicine. Local folk classification recognises the presence of different ethno-varieties on the basis of fruit and nut characters. In the present study, 176 trees representing 44 ethno-varieties from three farming systems of Uganda were assessed to determine the patterns of morphological variation and establish the congruence between morphological variation and folk classification. The results show high variation in pulp weight (CV = 35.9 %), stem diameter (CV = 28.48 %), fruit weight (CV = 27.81 %) and canopy diameter (CV = 26.69 %). There was a strong positive correlation between pulp and fruit weight (r = 0.963, p < 0.001), leaf length and leaf width (r = 0.652, p < 0.001) and between petiole length and leaf length (r = 0.788, p < 0.001). There was no underlying quantitative morphological structuring among the 44 ethno-varieties. Hierarchical cluster analysis using quantitative morphometric data produced three groups without clear aggregation based on ethnographic or geographic separation. However, a combination with qualitative traits as perceived by farmers provided good congruence with folk classification. Quantitative morphological data alone does not resolve any discrete forms of V. paradoxa that are related to folk classification. There is need to utilise biochemical and molecular markers to unravel the underlying variation for use in selection and improvement of shea butter tree ethno-varieties.     

Diagnostics of hydromorphism in soils of autonomous positions on the Severo-Sos’vinsk Upland (Western Siberia)

The complex studies of hydromorphism features in taiga weakly differentiated soils using morphological (color), chemical (iron content in different extracts, indicators of reducing conditions (IRIS)), and geobotanic (using the Ramenskii scale) methods have led to ambiguous conclusions. In all the soils, surface gleying was manifested. According to the results obtained by different methods, the maximum reduction processes were related to either the sublitter or the next deeper horizon. The Schwertmann coefficient, the criterion of Bodegom, and the Ramenskii scale indicated an increase of hydromorphism in the soils studied in the following sequence: the lower part of the ridge slopes drained by the small gullies < the middle part of the slopes < the flat tops of the ridges < the depression between the ridges. The morphological diagnostics of gleying proved to be a less sensitive method, which can recognize only the most contrasting hydromorphic soils. The lower horizons in some taiga soils have a bluish gray color probably not related to the recent soil hydromorphism.     

The use of individual tree statistics to quantify effects in an ‘acid mist’ experiment with mature trees

Mature trees of a single clone of Sitka spruce (Picea sitchensis (Bong.) Carr.) growing in the field were exposed to simulated acid mist at pH 2.5 over three successive years. The growth of each tree in the acid mist treatment, in terms of the stem area increment, was related to the pattern of growth of the untreated trees at the site during 1991 and 1992. In 1993, the effects of stopping the acid mist treatment on half of the treated trees was investigated by comparing the actual growth against that predicted relative to the untreated trees on the basis of the previous years' data. The prediction of growth from one year to the next was consistently too small for the smallest acid-misted trees, suggesting that the growth rates relative to the untreated trees were increasing with time. Relative to the trees which continued to receive acid mist, however, the smaller trees which received no further acid mist in 1993 grew less than predicted, but there was a significantly greater growth than predicted for the largest recovering trees. Results from the individual tree modelling approach showed that a 10% change in relative stem area increment would be detectable at the 5% level, using a block of 4 trees as a treatment unit. The statistical techniques used are alternatives to conventional ANOVA calculations in determining statistically significant treatment effects where numbers of replicates are small.     

Effects of leguminous plant residues and NPK fertilizer application on the performance of yam (Dioscorea rotundata ‘c.v.’ ewuru) in south-western Nigeria

The effects of cultivating and incorporating residues of previous tropical kudzu (Pueraria phaseoloides) and soybean (Glycine max) with application of NPK fertilizer on yam performance were evaluated at the teaching and research farm, LAUTECH, Nigeria. There were nine treatments: incorporation of legume residues (5 t DM ha^?1), application of recommended fertilizer rate for yam (90–50–75 kg NPK ha^?1) in the zone or 50% of recommended rate (45–25–37.5 kg NPK ha^?1), alone and in combination with residues and a control without residues or fertilizer in a randomized complete block design. Cultivation of previous legumes reduced soil nematode population (>200%) compared with no legumes. For both years, application of Pueraria residues improved tuber yield by an average of 15.8% compared with control. Fertilizer application enhanced arbuscular mycorrhizal (AM) colonization of yam roots but AM colonization was lower (～50%) in plots where Pueraria residues were incorporated compared with other plots. Combined application of plant residues with fertilizer improved soil organic carbon, total N, exchangeable Ca and Mg compared with application of NPK fertilizer. From these results, it is concluded that half of the recommended NPK rate may be adequate and incorporation of residues with reduced NPK fertilizer application may be a sustainable soil fertility management option for continuous yam production.     

Breeding of a practical rice line ‘TJTT8’ for phytoextraction of cadmium contamination in paddy fields

ABSTRACT

Previously, we showed that qCdp7, an allele identified in the high-Cd-accumulating indica rice variety ‘Jarjan,’ is associated with effective phytoextraction of Cd from paddy soils. However, ‘Jarjan’ may not be practical for phytoextraction because it is susceptible to seed shattering and culm lodging, which are unfavorable traits for mechanical rice harvesting. In this study, to develop a practical rice line for phytoextraction, we introduced the qCdp7 allele into ‘Tachisugata,’ a rice variety with a nonshattering habit and lodging resistance, to produce a new high-Cd-accumulating rice line designated ‘TJTT8.’ This line inherited high-Cd accumulation and brown pericarps from ‘Jarjan’ and a nonshattering habit and lodging resistance from ‘Tachisugata;’ all of these traits are necessary for rice intended for Cd phytoextraction in Japan. Backcross inbred lines (BILs) were produced by two backcrosses to ‘Tachisugata’ after a cross between ‘Jarjan’ and ‘Tachisugata.’ ‘TJTT8’ was selected from the BILs by means of marker-assisted selection and phenotypic evaluation. When ‘TJTT8,’ the parents, and ‘Cho-ko-koku’ which is a high-Cd-accumulating indica variety were cultivated in Cd-contaminated paddy fields in four locations in Japan, ‘TJTT8’ exhibited lodging resistance and shattering resistance that were higher than those of ‘Jarjan’ and ‘Cho-ko-koku’ and equivalent to those of ‘Tachisugata.’ ‘TJTT8’ accumulated Cd in the aerial parts of the plants at concentrations ranging from 6.5 to 22.7 mg m^?2: it showed significantly higher Cd accumulation than ‘Tachisugata’ and was equivalent to ‘Jarjan’ and slightly superior to ‘Cho-ko-koku.’ Soil Cd concentration was estimated to have been reduced by 8.7–33.6% based on the amount of Cd accumulation in the aerial parts of the plants. Thus, we succeeded in using the qCdp7 allele to produce a practical rice line for Cd phytoextraction by improving several agronomic traits for compatibility with Japanese cultivation systems.     

Effects of a ‘one film for 2 years’ system on the grain yield,water use efficiency and cost-benefit balance in dryland spring maize (Zea mays L.) on the Loess Plateau,China

‘One film for 2 years’ (PM2) has been proposed as a practice to control the residual film pollution; however, its effects on grain-yield, water-use-efficiency and cost-benefit balance in dryland spring maize production have still not been systematically explored. In this study, we compared the performance of PM2 with the annual film replacement treatment (PM1) and no mulch treatment (CK) on the Loess Plateau in 2015–2016. Our results indicated the following: (1) PM2 was effective at improving the topsoil moisture (0–20 cm) at sowing time and at seedling stage, but there was no significant influence on soil water storage, seasonal average soil moisture or evapotranspiration; (2) PM2 induced significantly higher cumulative soil temperatures compared to CK, and there was no significant difference between PM2 and PM1; (3) no significant differences were identified in grain-yield and water-use-efficiency between PM1 and PM2, and compared to CK, they improved by 16.3% and 15.5%, respectively; (4) because of lower cost of plastic film, tillage, film laying and remove in PM2, economic profits improved by 21% and 70% compared to PM1 and CK. This research suggested that PM2 was effective at alleviating the spring drought and was beneficial in reducing poverty traps in dryland.     

Langzeitwirkung der stickstoffdüngung Iosdv—standort limburgerhof (deutschland) in der reihe ‘internationale organische stickstoffdauerdüngungsversuche’

Die Landwirtschaftliche Versuchsstation Limburgerhof der BASF Aktiengesellschaft ist seit 1987 auch ‘IOSDV‐Standort. Auf einem lehmigen Sandboden werden verschiedene organische Düngungsvarianten (OD1 = ohne organische Düngung—OD2 = Stroh‐ZGülledüngung, Zwischenfruchtbau—OD3 = Strohdüngung, Zwischenfruchtbau + 50 kg/ha N) bei steigendem N‐Mineraldüngeraufwand in der Fruchtfolge ‘Körnermais—Winterweizen—Wintergerste’ geprüft. Bei den Getreidearten wird zudem der Einfluß von gezielten Pflanzenschutzmaßnahmen zur Krankheitsbekämpfung und Standfestigkeitsverbesserung auf den N‐Entzug ermittelt. Im einzelnen zeigt sich im Mittel der Kulturen und Anbaujahre:

1. Ohne N‐Düngung (N₀‐Stufe) differenzieren sich beim Vergleich der organischen Düngungsvarianten die Korn‐ und Stroherträge am stärksten, um sich mit steigender N‐Düngung immer mehr anzunähern.

2. In der N₁‐Stufe (? Kulturen = 77 kg/ha N) beläuft sich die Leistung der mineralischen N‐Düngung bei

OD1 auf 32,8 kg Körner pro 1 kg N

OD2 auf 23,7 kg Körner pro 1 kg N

OD3 auf 25,4 kg Körner pro 1 kg N

3. Bezogen auf die N₁‐Stufe beträgt die Leistung der N‐Mineraldüngung, die zum biologischen Höchstertrag in den einzelnen organischen Düngungsvarianten führt, mit

180 kg/ha N bei OD1 = 14,3 kg Körner pro lkg N

140 kg/ha N bei OD2 = 9,0 kg Körner pro 1 kg N

153 kg/ha N bei OD3 = 13,6 kg Körner pro 1 kg N

4. Die vereinfachten N‐Bilanzen erreichen im 8‐jährigen Mittel über die 3‐feldrige Fruchtfolge im Bereich von N₀‐N₄ Summenwerte zwischen

‐ 166 und + 61 kg/ha N bei OD1

+ 98 und +475 kg/ha N bei OD2

‐ 115 und + 227 kg/ha N bei OD3

5. Mit steigendem N‐Angebot nimmt die Bedeutung von gezielten Pflanzenschutzmaßnahmen zur Ertragsund Qualitätssicherung von Getreide zu.

6. Die N‐Ausnutzung der Gülle hat sich im Verlauf der Versuchsdauer verbessert.

7. Die N‐Ausnutzung der Mineraldüngung schwankt über die Fruchtfolge in Abhängigkeit der N‐Stufen und organischen Düngung zwischen 53% und 69%.

8. In einer Synopse von wichtigen Wirkungsparametern der organischen und mineralischen N‐Düngung werden diejenigen Ertragsverhältnisse als Ergebnis bestimmter Düngungsvarianten herausgestellt und diskutiert, die gleichsam das Optimum innerhalb der einzelnen Anbausysteme darstellen können hinsichtlich Vereinbarkeit von Ökonomie und Ökologie unter den gegebenen Standortverhältnissen.     

Water budget of the soils of sand massifs (with the Ust’-Kundryuchensk massif in rostov oblast as an example)

Sand massifs in the steppe zone with coarse-textured sandy or loamy sandy soils are mainly characterized by the percolative type of the soil water regime. The annual precipitation penetrating into the groundwater through the aeration zone varies from 80% in the barren sands to 30% and lower in the overgrown sands. The study of the water budget of the Ust??-Kundryuchensk sand massif with an area of 15800 ha indicates that the total volume of the annual groundwater outflow from the massif reaches 10.5 million m³. The water discharged all year round from the sand massif into the Kundryuch??ya and Severskii Donets rivers is fresh and ultrafresh. It contributes to the water discharge of the rivers and desalinates the river water. This is an important nature-protection function of the sand massif.     

Optimum Phosphorus Concentration for Growth of Catharanthus roseus (L.) G. Don ‘Pacifica White’ in a Subirrigation and Top Watering System

The objective of this study was to quantify the optimum rates of water-soluble phosphorus (P) on the growth of Catharanthus roseus (L.) G. Don ‘Pacifica White’ in soilless media in a recirculating subirrigation and top watering system. The experiment was designed so that only P varied between treatments; nitrogen (N), ammoniacal N to nitrate N ratio, and potassium (K) content were held constant. Media pH decreased with increasing P concentration in the nutrient solution in both the subirrigated and top-watered plants. Shoot N, P, K, magnesium, manganese, zinc, and copper were in general greater in the subirrigated plants when compared to top-watered plants. Shoot calcium, sulfur, iron, aluminum, and boron were greater in top-watered plants when compared to subirrigated plants. Optimal plant growth was achieved at ≥0.5 mM P in the subirrigated and top-watered plants, which is lower than what is usually commercially applied. Subirrigated plants were of greater quality and dry mass regardless of P concentration in the nutrient solution, when compared to top-watered plants.