Identification of resistant sources in Cicer species to Liriomyza cicerina

Summary Leaf miner (Liriomyza cicerina Rond.) causes considerable damage to chickpea (Cicer arietinum L.) in West Asia, North Africa and Southern Europe. Use of resistant cultivar is the economical method of control. Screening of over 7000 germplasm accessions did not result in identification of highly resistant accessions to this insect. Therefore, 200 accessions of eight wild Cicer species were evaluated in search of resistance to leaf miner between 1988 and 1991 at ICARDA, Syria. Accessions of Cicer species were screened under natural insect infestation in the field during spring (March–June), along with a susceptible-cum-indicator line. Two accessions of C. cuneatum (ILWC-40 and -187) and 10 accessions of C. judaicum (ILWC-44, -46, -56, -57, -58, -95, -103, -196, -206, and -207) were rated 2 on a 1–9 scale, where 1 = free from any damage and 9 = maximum damage. Another 18 lines of C. judaicum, four lines of C. pinnatidum and one line of C. reticulatum were rated 3 (resistant). Currently three species are incompatible in crossing with chickpea, but C. reticulatum is being used in breeding programme.Joint contribution from ICARDA and ICRISAT (Inter-national Crops Research Institute for the Semi-Arid Tropics), Patancheru P.O., AP 502 324, India.     

INHERITANCE OF RESISTANCE TO IRON DEFICIENCY CHLOROSIS IN CHICKPEA (CICER ARIETINUM L.)

Iron (Fe)-deficiency chlorosis causes considerable yield losses in chickpea (Cicer arietinum L.) when susceptible genotypes are grown in calcareous soils with high pH. The most feasible method for alleviating Fe deficiency is the selection of suitable cultivars resistant to Fe deficiency chlorosis. ICC 6119 (desi type), which is Fe-deficient chlorosis, was crossed with CA 2969 and Sierra (kabuli types), resistant to Fe deficiency chlorosis. Inheritance of resistance to Fe deficiency in chickpea revealed that the resistance was controlled by a single dominant gene in these genotypes crossed. A negative selection for resistance to Fe deficiency chlorosis will be effective after segregating generations.     

Adaptation of some introduced eragrostis species to calcareous soil and acid mine spoil

Abstract

Plant growth is frequently limited by Fe‐related chlorosis on calcareous soils and by mineral toxicities on strongly acid soils and mine spoils. Better adapted varieties are needed for both soil situations, which are not always economically correctable. In a search for such geraplasm, 4 species (20 accessions) of Eragrostis were grown in greenhouse pots of a calcareous soil at pH 7.3. Two species were also compared on acid mine spoil at pH 3.5 and 4.7.

Species, and accessions within species, differed significantly in tolerance to the calcareous soil, as measured by susceptibility to chlorosis and yield of plant tops. The range in top yield was 11‐fold for accessions of Eragrostis capensis, 3‐fold for Eragrostis lehmanniana, and 1.7‐fold for Eragrostis superba. Eragrostis plana (P.I. 364340) was more tolerant to acid mine spoil (pH 3.5) but less tolerant to calcareous soil (pH 7.3) than Eragrostis superba (P.I. 364833).

Chlorosis and poor growth of certain accessions on calcareous soil (pH 7.3) were not explained by specific mineral deficiencies or toxicities. However, the tops of chlorosis‐susceptible accessions had lower ratios of Fe/Mn, Fe/Zn, and Fe/Cu than those of chlorosis‐resistant accessions. This imbalance is believed to interfere with Fe metabolism in plant tops.

Results suggested that superior strains of Eragrostis species can be selected for adaptation to calcareous or acid soils and that certain accessions characterized in these studies can be useful in studying the physiological mechanisms of mineral stress resistance in plants.     

Effect of integrated management on Fusarium wilt progression and grain yield of chickpea in Syria

Fusarium wilt, caused by Fusarium oxysporum Schlechtend.: f. sp. ciceris (Padwick) Matuo & K. Sato, is a major production problem in many countries. A study was conducted to develop an integrated management of Fusarium wilt of chickpea using genotypes, sowing dates (January as early sowing and March/April as spring sowing) and fungicide seed treatments under natural infested plots in research plots and farmers’ fields 2007–2009 cropping seasons. In most cases, sowing date and fungicides did not affect disease parameters and seed yield. Chickpea genotypes showed significant differences in seed yield but different responses for disease parameters. Averaged over locations and seasons, the rate of disease development was higher in early (0.035 units day^?1) than spring (0.023 units day^?1) sowing. Chickpea genotypes showed different responses in affecting rate of disease development and cumulative wilt incidence in early and late sowing periods. Higher mean seed yield (1.3 t ha^?1) was recorded in early than late sowing (1.0 t ha^?1) of chickpea. The average seed yield reduction due to spring sowing ranged from 9% to 60% and highest yield losses were observed in FLIP-97–706 and Ghab-3. This study showed that integrating January sowing with genotypes having good levels of resistance for Fusarium wilt and Ascochyta blight helps farmers to narrow chickpea yield gaps in Syria.     

Cover crop growth and impact on N leaching as affected by pre‐ and postharvest sowing and time of incorporation

In Northern Europe, cover crops are traditionally established before spring crops by undersowing, but some cover crops might also have an effect if preharvest sown before spring crops and even winter crops. The effects of cover crop sowing date, sowing technique and succeeding main crop on biomass production, N uptake, nitrate leaching and soil inorganic N were tested in lysimeters and in the field. Cruciferous cover crops (oil radish, white mustard) were sown preharvest by broadcasting into winter wheat in July and were allowed to grow until a following winter wheat was established in September. Other preharvest cover crops were left in place until late autumn. For comparison, the same cruciferous cover crops were established postharvest after light harrowing. Perennial ryegrass undersown in spring barley was also included. Aboveground N uptake in preharvest cover crops amounted to a maximum of 24 kg N/ha in September before sowing winter wheat. When left until late autumn, preharvest oil radish took up a maximum of 66 kg N/ha, and ryegrass and postharvest cover crops 35 kg N/ha. Preharvest establishment of cruciferous cover crops before a spring‐sown crop thus seems promising. The soil was depleted of inorganic N to the same extent in late autumn irrespective of cover crop type, sowing time and technique within winter wheat or spring barley. However, the reduction in nitrate leaching of preharvest cover crops incorporated after 2 months and followed by winter wheat was only half of that achieved by cover crops left until late autumn or spring.     

Evaluation of annual wild <Emphasis Type="Italic">Cicer</Emphasis> species for drought and heat resistance under field conditions

About 90% of chickpea (Cicer arietinum L.) in the world is grown under rainfed conditions where it is subjected to drought and heat stress. Unlike the cultivated chickpea, annual wild Cicer species possess sources of resistance to multiple stress; annual wild Cicer species were therefore evaluated for resistance to drought and heat stress. Eight annual wild Cicer species (Cicer bijugum, C. chorassanicum, C. cuneatum, C. echinospermum, C. judaicum, C. pinnatifidum, C. reticulatum, and C. yamashitae) were compared with special checks, the cvs ICC 4958 and FLIP 87-59C (drought resistant) and ICCV 96029 (very early double-podded). ILC 3279 and 8617 as drought susceptible checks were sown after every 10 test lines. Yield losses due to drought and heat stress in some accessions and susceptible checks (ILC 3279 and ILC 8617) reached 100%. Accessions were evaluated for drought and heat resistance on a 1 (free from drought and heat damage)−9 (100% plant killed from drought and heat) visual scale. Four accessions of C. reticulatum and one accession of C. pinnatifidum were found to be as resistant to drought and heat stress (up to 41.8°C) as the best checks. C. reticulatum should be taken account in short term breeding programs since it can be crossed with the cultivated chickpea.     

Sources of winter hardiness in wild lentil

Summary In high altitude areas (> c. 850 m elevation) in west Asia and north Africa, lentil (Lens culinaris) is grown as a spring crop to avoid severe winter cold. But late fall-sown lentil with winter hardiness has higher yield potential in these areas. In this study a total of 245 accessions of wild lentil, 10 of cultivated lentil and three accessions of Vicia montbretii (syn. L. montbretii) were evaluated for winter hardiness in Syria and Turkey during the 1991/92 season. The absolute minimum temperatures were-16°C in Syria and-18.9°C in Turkey and the susceptible indicators were killed at both locations showing that the cold was sufficient for screening. Although winter hardiness was assessed as percentage of survived plants in Syria and as a visual damage rating on a 1–9 scale in Turkey, there was agreement between the winter hardiness ratings with a correlation of r=–0.56, P<0.001. Accessions of L. culinaris ssp. orientalis exhibited the highest level of winter hardiness, on average; whereas accessions of L. nigricans ssp. ervoides were the most susceptible. Correlations revealed that winter hardiness was concentrated among accessions originating from high elevation areas.     

Time of emergence of Rumex crispus L. as affected by dispersal time,soil cover,and mechanical disturbance

Abstract

Emergence pattern of the perennial weed species Rumex crispus L. was studied under semi-field conditions. Seeds from three populations were harvested from the mother plants and sown in pots buried in an experimental field, either in late autumn or after winter storage at outdoor temperatures. Seeds were sown on the soil surface or covered by a 2-cm soil layer. In addition, some of the seeds sown in autumn were also subjected to mechanical disturbance in autumn or in spring. Population and soil cover both had a strong effect on total emergence. The light requirement of the species for germination was indicated by a higher rate of emergence from seeds sown on the soil surface than from covered seeds. Sowing date influenced the timing of emergence but not the total emergence. Autumn sowing led to earlier and more concentrated emergence, while seedlings from spring-sown seeds showed a more intermittent emergence pattern. Stirring after sowing had a positive effect on emergence compared with emergence from undisturbed, covered seeds. In all populations and treatments, emergence continued throughout the growing season, contradicting earlier findings that R. crispus seeds germinate mainly in early spring and autumn, and enter secondary dormancy during summer. The delay of emergence in seeds that had remained on the mother plant over winter indicates a certain level of dormancy, which was gradually broken in early summer.     

Leaching of nitrate and phosphorus after autumn and spring application of separated solid animal manures to winter wheat

Animal slurry can be separated into solid and liquid manure fractions to facilitate the transport of nutrients from livestock farms. In Denmark, untreated slurry is normally applied in spring whereas the solid fraction may be applied in autumn, causing increased risk of nitrate and phosphorus (P) leaching. We studied the leaching of nitrate and P in lysimeters with winter wheat crops (Triticum aestivum L.) after autumn incorporation versus spring surface application of solid manure fractions, and we compared also spring applications of mineral N fertilizer and pig slurry. Leaching was compared on a loamy sand and a sandy loam soil. The leaching experiment lasted for 2 yr, and the whole experiment was replicated twice. Nitrate leaching was generally low (19–34 kg N/ha) after spring applications of mineral fertilizer and manures. Nitrate leaching increased significantly after autumn application of the solid manures, and the extra nitrate leached was equivalent to 23–35% of total manure N and corresponded to the ammonium content of the manures. After spring application of solid manures and pig slurry, only a slight rise in N leaching was observed during the following autumn/winter (<5% of total manure N). Total P leaching was 40–165 g P/ha/yr, and the application of solid manure in autumn did not increase P leaching. The nitrogen fertilizer replacement value of solid manure N was similar after autumn and spring application (17–32% of total N). We conclude that from an environmental perspective, solid manure fractions should not be applied to winter wheat on sandy and sandy loam soils under humid North European conditions.     

Identification of duplicates and fingerprinting of primary and secondary wild annual <Emphasis Type="Italic">Cicer</Emphasis> gene pools using AFLP markers

Wild annual Cicer gene pools contain valuable germplasm for chickpea improvement programs. Previous research showed that duplication might exist in accessions collected from these gene pools, which would hinder chickpea breeding and related research. AFLP (amplified fragment length polymorphism) markers were used to fingerprint the world collections of the primary and secondary gene pools including C. reticulatum Lad., C. bijugum K.H. Rech., C. judaicum Boiss. and C. pinnatifidum Jaub. et Sp. Duplicates were detected in a total of 24 accessions in both the gene pools, highlighting the necessity to fingerprint the germplasm. Genotypic difference was detected as gene pool specific, species specific and accession specific AFLP markers. These were developed into fingerprinting keys for accession identification between and within species and gene pools. Use of AFLP markers to detect duplicates and to identify accessions is a reliable method which will assist in the characterisation and use of wild annual Cicer germplasm in chickpea improvement programs. We recommend the procedure presented in this paper as a standard approach for the precise genetic identification and characterisation of future world collections of wild Cicer, to keep germplasm integrity and to benefit chickpea breeding and related research programs.     

Genetic diversity in European accessions of the Barley Core Collection as detected by isozyme electrophoresis

Genetic diversity in 79 European accessions of the Barley Core Collections was surveyed using isozyme electrophoresis. A total of 26 alleles were observed at the ten isozyme loci. All loci were polymorphic except Pgd-1 which was monomorphic. The comparison of the results with those of previous studies indicates that most of the alleles occurring in the European Barley are also observed in this set of the European Barley Core Collections. Only five alleles (Est-1 Al; Est-5 Ag, Te; Pgi-1 C and Ndh-2 B) were absent. Nine of 26 alleles were rare alleles, which were detected only in one or two accessions. Moreover, most of rare alleles were detected in 6-rowed winter barley. It is very important to include rare alleles for maximising the genetic variations in core collections. In the set of European Barley Core Collection, 6-rowed barley contained larger diversity than 2-rowed barley; winter type contained larger diversity than spring type. The cluster analysis separated 79 accessions into three major groups. Group I is more complex and comprised 2-rowed spring, 2-rowed winter and 6-rowed winter barley. In this group, 18 accessions in the cluster A and 14 accessions in the cluster B possessed identical genotypes as judged from the ten isozyme data. Principal coordinate analysis could not clearly separate the spring cultivars from the winter barley lines, as well as not separate 2-rowed from 6-rowed barley.     

Analysis of Genetic Diversity in the Brassica napus L. Gene Pool Using SSR Markers

Genetic diversity throughout the rapeseed (Brassica napus ssp. napus) primary gene pool was examined by obtaining detailed molecular genetic information at simple sequence repeat (SSR) loci for a broad range of winter and spring oilseed, fodder and leaf rape gene bank accessions. The plant material investigated was selected from a preliminary B. napus core collection developed from European gene bank material, and was intended to cover as broadly as possible the diversity present in the species, excluding swedes (B. napus ssp. napobrassica (L.) Hanelt). A set of 96 genotypes was characterised using publicly available mapped SSR markers spread over the B. napus genome. Allelic information from 30 SSR primer combinations amplifying 220 alleles at 51 polymorphic loci provided unique genetic fingerprints for all genotypes. UPGMA clustering enabled identification of four general groups with increasing genetic diversity as follows (1) spring oilseed and fodder; (2) winter oilseed; (3) winter fodder; (4) vegetable genotypes. The most extreme allelic variation was observed in a spring kale from the United Kingdom and a Japanese spring vegetable genotype, and two winter rape accessions from Korea and Japan, respectively. Unexpectedly the next most distinct genotypes were two old winter oilseed varieties from Germany and Ukraine, respectively. A number of other accessions were also found to be genetically distinct from the other material of the same type. The molecular genetic information gained enables the identification of untapped genetic variability for rapeseed breeding and is potentially interesting with respect to increasing heterosis in oilseed rape hybrids.     

RAPD and ISSR fingerprinting in cultivated chickpea (<Emphasis Type="Italic">Cicer arietinum</Emphasis> L.) and its wild progenitor <Emphasis Type="Italic">Cicer reticulatum</Emphasis> Ladizinsky

Detection of genetic relationships between 19 chickpea cultivars and five accessions of its wild progenitor Cicer reticulatum Ladizinsky were investigated by using RAPD and ISSR markers. On an average, six bands per primer were observed in RAPD analysis and 11 bands per primer in ISSR analysis. In RAPD, the wild accessions shared 77.8% polymorphic bands with chickpea cultivars, whereas they shared 79.6% polymorphic bands in ISSR analysis. In RAPD analysis 51.7% and 50.5% polymorphic bands were observed among wild accessions and chickpea cultivars, respectively. Similarly, 65.63% and 56.25% polymorphic bands were found in ISSR analysis. The dendrogram developed by pooling the data of RAPD and ISSR analysis revealed that the wild accessions and the ICCV lines showed similar pattern with the dendrogram of RAPD analysis. The ISSR analysis clearly indicated that even with six polymorphic primers, reliable estimation of genetic diversity could be obtained, while nearly 30 primers are required for RAPD. Moreover, RAPD can cause genotyping errors due to competition in the amplification of all RAPD fragments. The markers generated by ISSR and RAPD assays can provide practical information for the management of genetic resources. For the selection of good parental material in breeding programs the genetic data produced through ISSR can be used to correlate with the relationship measures based on pedigree data and morphological traits to minimize the individual inaccuracies in chickpea.     

Tolerance of chickpea (Cicer arietinum L.) lines to root-knot nematode, Meloidogyne javanica (Treub) Chitwood

The root-knot nematode, Meloidogyne javanica (Treub) Chitwood is an important parasite of chickpea (Cicer arietinum L.). Four chickpea genotypes were evaluated for tolerance to M. javanica in naturally infested fields at three locations. Each genotype was evaluated for number of galls, gall size, root area covered with galls and number of egg masses produced. All the cultivars were susceptible or highly susceptible. Seed yield, weight of 100 undamaged seeds, total dry matter and plant height were compared with checks. Chickpea cultivar Annigeri and a local check were used as nematode susceptible checks in all locations. The four promising nematode tolerant genotypes produced significantly greater yield and total dry matter than the checks in fields naturally infested with M. javanica at three locations. These M. javanica tolerant lines represent new germplasm and they are available in the chickpea genebank at the International Crops Research Institute for the Semi-Arid Tropics (ICRISAT) bearing the identification numbers ICC 8932, ICC 11152, ICCV 90043 and ICCC 42.     

Sampling strategies and screening of chickpea (<Emphasis Type="Italic">Cicer arietinum</Emphasis> L.) germplasm for salt tolerance

Six hundred accessions of chickpea (Cicer arietinum L.) landraces and its wild relatives from 28 different countries, available at Australian Temperate and Field Crops Collection (ATFCC) were screened for tolerance to salt under greenhouse conditions using three sampling strategies; (1) random sampling of 200 accessions from different countries, (2) restricted random sampling of 200 accessions from geographical regions with salinity problems and high diversity (Middle East and West & South Asia) and (3) as for strategy 1 but with a reduced representation of accessions from the geographical regions used in strategy 2. Degree of salt tolerance was based on necrosis scores and shoot biomass reduction relative to unstressed controls at harvest after subjecting stressed plants to salt treatment from 21 to 42 days after sowing. There was a wide variation in salinity tolerance determined by both measures. For sampling strategies 1, 2 and 3 respectively; 24, 28 and 14% of accessions were salt tolerant. Accessions from the middle east and south Asian (regions with salinity problem, a long history of chickpea cultivation and high diversity) gave a higher probability (P < 0.01) of getting salt tolerant accessions.     

全膜双垄沟不同覆膜时期对玉米土壤水分和产量的影响

针对甘肃省旱作农业区年降水量少、季节分布不均匀、玉米生产中春旱严重的问题,采用田间试验的方法研究了全膜双垄沟4种不同覆膜时期对旱地玉米生育时期、土壤水分变化、水分利用效率、产量及经济效益的影响。结果表明:秋覆膜优于早春顶凌覆膜、玉米播前覆膜和晚春播种时覆膜,即早覆膜优于晚覆膜。全膜双垄沟秋覆膜增加了降水利用率和水分利用效率,降水利用率为70.21%,产量为10039.34kg/hm2,比播前覆膜8036.67kg/hm2增产24.92%,水分利用效率36.01kg/hm2·mm,比播前覆膜27.10kg/hm2·mm提高32.88%。全膜双垄沟秋覆膜可明显减少冬春季土壤水分的无效蒸发,增产效果明显,是旱作区进一步挖掘降水潜力和高产田创建的有效途径。     

Evaluation of yield and agronomic traits and their genetic variation in 488 global collections of Brassica napus L.

It is important to evaluate yield and agronomic traits when selecting for elite lines in Brassica napus L. In this study, 488 global collections of B. napus L. were evaluated for yield and agronomic traits during two consecutive years under growing conditions in central China. A series of phenotypic data for yield and agronomic traits were obtained. Large variations in yield and agronomic traits were found among these accessions, making selection possible for these characters. Chinese accessions, in general, tended to have higher plot yield (POY), higher seed yield per plant (PY), higher thousand-seed weight (TSW), more seeds per silique (SS), and fewer siliques per plant (PS) than foreign accessions. Comparing winter, semi-winter, and spring accessions, semi-winter accessions tended to have the highest POY, highest PY, highest TSW, most SS and fewest PS. Genotypic variation for TSW accounted for 71.23 % of the total variation, and it was the highest for all 12 of the phenotypic traits. Significant correlations were observed between different traits. Principal component analysis (PCA) revealed that significant variation among the traits with the first four principal components could explain 49.8 % of the total variation. Three major groups (winter, spring and semi-winter oilseed rape accessions) could be distinguished when projecting the accessions onto the first two PCAs. The information on variations in yield and agronomic traits detected in this study provided useful parents for rapeseed breeding. Moreover, the phenotypic data on yield and agronomic traits obtained may be used in our subsequent genome-wide association studies for B. napus.     

贵州高原夏秋麦与冬播麦生育特性的比较

研究结果表明，由于高温对小麦春性品种生育的促进作用，夏秋麦比冬播麦分蘖少，秆矮叶面积小，干物质积累少，生育期短，产量低。单位面积穗数不足是夏秋麦高产的主要限制因子。多数年份夏秋麦穗粒数和千粒重比冬播麦低，气候生态因素是决定二者大小的主要环境因子。     

近50年长三角地区季节的气候变化特征

根据长三角地区31个站点1961-2010年逐日气温资料,按照国家标准进行季节划分,在研究四季长度和起始时间变化特征的基础上,利用Mann-Kendall检验、等值线等方法对季节的时间变化趋势和空间分布特征进行研究。结果表明,时间变化上,长三角地区夏季长度有极显著的增加趋势(P0.01),春、夏两季的起始日期有显著的提前趋势(P0.01和P0.05)。空间分布上,春、秋季节长度由内陆向沿海增加,夏季长度由北向南递增,冬季长度由北向南递减。四季长度变化趋势的空间结构为:春、夏季以延长为主,秋、冬季主要表现为缩短,其中夏季长度的延长最为显著(P0.01)。四季起始时间空间分布为:春、夏季南部入季早,秋、冬季北部入季早;起始时间变化趋势的空间结构为:春、夏季为一致的提早趋势;秋、冬季以延后为主。     

Changes in N leaching and crop production as a result of measures to reduce N losses to water in a 6‐yr crop rotation

The effects of various measures introduced to increase nitrogen (N)‐use efficiency and reduce N losses to water in a 6‐yr crop rotation (winter wheat, spring barley, green manure, winter wheat, spring barley, spring oilseed rape) were examined with respect to N leaching, soil mineral N (SMN) accumulation and grain yield. An N‐use efficient system (NUE) with delayed tillage until late autumn and spring, direct drilling of winter wheat, earlier sowing of winter and spring crops and use of a catch crop in winter wheat was compared with a conventional system (CON) in a field experiment with six separately tile‐drained plots in south‐western Sweden during the period 1999–2011 (two crop rotation cycles). Total leaching of NO₃‐N from the NUE system was significantly 46 and 33% lower than in the CON system during the first and second crop rotation cycle, respectively, with the most pronounced differences apparently related to management strategies for winter wheat. Differences in NO₃‐N leaching largely reflected differences in SMN during autumn and winter. There was a tendency for lower yields in the NUE system, probably due to problems with couch grass. Overall, the measures for conserving N, when frequently used within a crop rotation, effectively reduced NO₃ concentrations in drainage water and NO₃‐N leaching losses, without severely affecting yield.