Evaluation of <Emphasis Type="Italic">Phaseolus acutifolius</Emphasis> A. Gray plant introductions under high temperatures in a controlled environment

Heat susceptibility is a cause of yield loss in common bean (Phaseolus vulgaris L.) in temperate and tropical lowland growing regions. Interspecific hybridization with related species that include tepary bean (Phaseolus acutifolius A. Gray) can potentially be used to transfer heat tolerance traits to common bean. This study evaluated 25 tepary bean plant introductions (PIs) following exposure to high-temperature (35 °C day/32 °C night) and control temperature (27 °C day/24 °C night) during reproductive development. These 25 PIs were selected for high yield potential in a 14 h photoperiod greenhouse environment. High temperature when compared to non-stress treatment resulted in a mean reduction in seed yield of 88.8% among tepary beans and caused 100% yield loss in common beans. Twelve P. acutifolius PIs exhibited negligible yield under heat-stress when compared to control treatment. Although yields of these accessions were low under very high-temperature conditions, PI 200902, PI 312637, PI 440785, PI 440788, and PI 440789 exhibited the highest yield component stability under the high temperature treatment.     

Nitrogen yield and nitrogen fixation of winter faba beans

Introducing autumn-sown legumes into Central European farming systems could be beneficial for addressing two challenges for European agriculture, i.e., the substantial deficit of protein sources for livestock and expected changes in agroclimatic conditions. Therefore, a two-year field experiment was conucted under Pannonian climate conditions in eastern Austria to assess nitrogen (N) yield and N fixation of several winter faba bean varieties from different European countries as compared to a spring faba bean. Winter wheat was used as a reference crop for estimating atmospheric N fixation. Winter faba beans were susceptible to frost damage especially in the harder of the two winters. Winter faba bean varieties could not achieve a higher grain yield and a higher grain N yield than the spring faba bean but had a higher grain N concentration (except for one variety). Grain yield and grain N yield of faba beans were severely impaired by drought in one year (with a mean of varieties of 8.3 g N m^?2, winter wheat: 6.4 g N m^?2); in the other year, grain N yield of faba beans considerably surpassed that of winter wheat (with a mean of varieties of 21.5 g N m^?2, winter wheat: 8.8 g N m^?2). After harvest, faba beans left higher nitrate residues in the soil, especially in the subsoil, and higher amounts of N in above-ground residues compared to winter wheat. Faba beans showed high N fixation under optimum conditions (with a mean of varieties of 21.9 g N m^?2) whereas drought considerably impaired N fixation (with a mean of varieties of 6.3 g N m^?2; with no differences between autumn- and spring-sown faba beans). In conclusion, growing winter faba bean varieties in eastern Austria did not result in higher grain yield, grain N yield, and N fixation compared to growing a spring faba bean.     

A study of variability in the Sicilian faba bean landrace ‘Larga di Leonforte’

In this paper molecular analysis, physical, technological, and chemical traits were used to estimate the level of variation on five accessions of a locally adapted Sicilian faba bean (Vicia faba L.) landrace named ‘Larga di Leonforte’. DNA analysis was performed using the Amplified Fragment Length Polymorphism (AFLP) molecular marker class and two other faba beans (cv. ‘Aguadulce Samba’—Spain—and landrace ‘Locale di Modica’—Sicily) were used as controls. Although the accessions of ‘Larga di Leonforte’ varied significantly for most of the agronomical and physical traits, this landrace generally had a heavy seed weight, short but large pods, and no more than two seeds per pod. This last characteristic allowed for erect pod angle attitude at maturity. Idratation data showed difference among accessions in seed weight at full hydration and in absorption rate at the very beginning of the hydration process, while any difference among accessions emerged in terms of cooking properties. The six AFLP Eco+3/Mse+3 different primer combinations applied in this research revealed different levels of polymorphism among the faba bean accessions and a total number of 346 amplicons were generated. Around 60% of amplicons displayed a polymorphic pattern among different accessions. Cluster analysis on morphological, technological, chemical and molecular data placed the all five ‘Larga di Leonforte’ accessions into a separated group, and the Sicilian material shares a fairly large amount of similarity with respect to the cultivar ‘Aguadulce Samba’ selected in Spain.     

Agrobiodiversity of eleven accessions of <Emphasis Type="Italic">Mucuna pruriens</Emphasis> (L.) DC. var. <Emphasis Type="Italic">utilis</Emphasis> (Wall. ex Wight) Baker ex Burck (velvet bean) collected from four districts of South India

Eleven accessions of an under-utilized legume, Mucuna pruriens (L.) DC. var. utilis (Wall. ex Wight) Baker ex Burck (velvet bean) were collected from four districts of South India and their agronomic characters were evaluated. The vegetative growth characters such as the germination percentage, plant height, number of leaves and branches per plant were recorded. The yield based characters such as the number of clusters/plant (4–14), number of flowers/cluster (3–15) and the fertility index (66–91%) were observed. The seed yield reaches 2.9–6.9 t/ha. The number of seeds per pod, seed weight and the seed recovery percentage were also calculated. The level of diversity in the agrobotanical traits of velvet bean observed in the present study could be of interest in a breeding programme.     

Preliminary screening and selection for cold tolerance in annual wild <Emphasis Type="Italic">Cicer</Emphasis> species

The study was aimed to select cold tolerant accessions of annual wild Cicer species in the highlands in the west Mediterranean area of Turkey. A total of 43 accessions of eight annual wild Cicer species was screened for cold tolerance and compared with the best cold tolerant cultivars, ILC 8262 and FLIP 93-53C. After the sensitive check, ILC 533, was killed, accessions were evaluated using a 1–9 scale. Three accessions of Cicer bijugum, 2 accessions of Cicer reticulatum and 2 accessions of Cicer echinospermum were highly cold tolerant, while 3 accessions of C. bijugum, 9 accessions of C. reticulatum, 2 accessions of C. echinospermum and 1 accession of Cicer pinnatifidum were cold tolerant. All accessions of Cicer judaicum were sensitive to cold. Whereas Cicer chorassanicum and Cicer cuneatum were killed, Cicer yamashitae was recorded as highly sensitive to cold. The cold tolerant accessions of annual wild Cicer species were superior to the best cultivar as far as hardiness is concerned.     

Biological nitrogen fixation in faba bean (Vicia faba L.) in the Ethiopian highlands as affected by P fertilization and inoculation

 N₂ fixation by leguminous crops is a relatively low-cost alternative to N fertilizer for small-holder farmers in developing countries. N₂ fixation in faba bean (Vicia faba L.) as affected by P fertilization (0 and 20 kg P ha^–1) and inoculation (uninoculated and inoculated) with Rhizobium leguminosarium biovar viciae (strain S-18) was studied using the ¹⁵N isotope dilution method in the southeastern Ethiopian highlands at three sites differing in soil conditions and length of growing period. Nodulation at the late flowering stage was significantly influenced by P and inoculation only at the location exhibiting the lowest soil P and pH levels. The percentage of N derived from the atmosphere ranged from 66 to 74%, 58 to 74% and 62 to 73% with a corresponding total amount of N₂ fixed ranging from 169 to 210 kg N ha^–1, 139 to 184 kg N ha^–1 and 147 to 174 kg N ha^–1 at Bekoji, Kulumsa and Asasa, respectively. The total N₂ fixed was not significantly affected by P fertilizer or inoculation across all locations, and there was no interaction between the factors. However, at all three locations, N₂ fixation was highly positively correlated with the dry matter production and total N yield of faba bean. Soil N balances after faba bean were positive (12–58 kg N ha^–1) relative to the highly negative N balances (–9–44 kg N ha^–1) following wheat (Triticum aestivum L.), highlighting the importance of rotation with faba bean in the cereal-based cropping systems of Ethiopia. Received: 13 January 2000     

N<Subscript>2</Subscript> fixation by faba bean (<Emphasis Type="Italic">Vicia faba</Emphasis> L.) in a gypsum-amended sodic soil

The response of faba bean to the application of four rates of gypsum (0, 2.5, 5.0, 10.0 t ha⁻¹) to a non-saline, alkaline sodic soil was measured in terms of grain yield, dry matter (DM) production, N accumulation and the proportional dependence of the legume on symbiotic N₂ fixation (P _atm). A yield-independent, time-integrated ¹⁵N-dilution model was used to estimate symbiotic dependence. A significant decrease in the exchangeable sodium percentage and significant increases in exchangeable Ca⁺⁺ and the Ca⁺⁺:Mg⁺⁺ ratio in the 0–10-cm soil layer were measured 30 months after application of 10 t ha⁻¹ gypsum. Despite low and erratic rainfall during crop growth, faba bean DM and N uptake responded positively to gypsum application. The symbiotic dependence of the legume at physiological maturity was little affected by sodicity (P _atm = 0.74 at zero gypsum and 0.81–0.82 at 2.5–10 t ha⁻¹ gypsum). The increase in fixed N due to gypsum application was mainly due to increases in legume DM and total N uptake. At 10 t ha⁻¹ of gypsum, faba bean fixed more than 200 kg N ha⁻¹ in above-ground biomass.     

Phosphorus uptake and rhizosphere properties of intercropped and monocropped maize, faba bean, and white lupin in acidic soil

Little information is available on phosphorus (P) uptake and rhizosphere processes in maize (Zea mays L.), faba bean (Vicia faba L.), and white lupin (Lupinus albus L.) when intercropped or grown alone in acidic soil. We studied P uptake and soil pH, carboxylate concentration, and microbial community structure in the rhizosphere of maize, faba bean, and white lupin in an acidic soil with 0–250 mg P (kg⁻¹ soil) as KH₂PO₄ (KP) or FePO₄ (FeP) with species grown alone or intercropped. All plant species increased the pH compared to unplanted control, particularly faba bean. High KP supply (>100 mg P kg⁻¹) significantly increased carboxylate concentration in the rhizosphere of maize. The carboxylate composition of the rhizosphere soil of maize and white lupin was significantly affected by P form (KP or FeP), whereas, this was not the case for faba bean. In maize, the carboxylate composition of the rhizosphere soil differed significantly between intercropping and monocropping. Yield and P uptake were similar in monocropping and intercropping. Monocropped faba bean had a greater concentration of phospholipid fatty acids in the rhizosphere than that in intercropping. Intercropping changed the microbial community structure in faba bean but not in the other corps. The results show that P supply and P form, as well as intercropping can affect carboxylate concentration and microbial community composition in the rhizosphere, but that the effect is plant species-specific. In contrast to previous studies in alkaline soils, intercropping of maize with legumes did not result in increased maize growth suggesting that the legumes did not increase P availability to maize in this acidic soil.     

Limited winter survival and compensation mechanisms of yield components constrain winter faba bean production in Central Europe

A substantial deficit of protein sources for livestock and expected changes in agro-climatic conditions are two challenges for European agriculture. Both can be addressed by introducing more autumn-sown legumes into Central European farming systems. Therefore, a three-year field experiment was conducted under Pannonian climate conditions in eastern Austria in which several winter faba bean varieties from different European countries were compared to a spring faba bean variety. Winter faba bean was susceptible to frost damage. Best overwintering was observed with the German variety Hiverna and the French variety Diva. Regarding overwintering, the first winter allowed for a clear differentiation between varieties, in the second winter, severe frost caused loss of almost all winter faba bean plants and in the third winter, which was mild, most varieties showed good overwintering. Grain yield of winter faba bean was mainly determined by variations of plants m^?2 (i.e. by overwintering) whereas compensatory mechanisms between yield components had a minor influence on yield formation. No grain yield advantage could be observed for winter faba bean varieties compared to the spring faba bean variety even in the year with good overwintering. Regarding yield components, winter faba bean had generally more shoots plant^?1 and a higher thousand kernel weight but spring faba bean tended to have more pods shoot^?1 and grains shoot^?1 whereas pods plant^?1, grains plant^?1 and grains pod^?1 generally did not differ. In conclusion, limited winter hardiness together with the minor influence of compensatory mechanisms between yield components on yield formation are serious constraints for increasing the cultivation of winter faba bean in Central Europe.     

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.     

Complementary resource use in intercropped faba bean and cabbage by increased root growth and nitrogen use in organic production

Intercropping can improve yield and nitrogen use efficiency in organic vegetable production by pairing crops with complementary resource use. An intercrop field experiment was conducted to determine yield, root growth and nitrogen (N) dynamics using faba bean (Vicia faba L.) grown as a vegetable and pointed cabbage (Brassica oleracea var. capitata cv. conica). Both crops were grown in monocropping (MC) and intercropping systems (IC). Minirhizotrons were used to measure root growth. Yield of pointed cabbage per metre row was 28% higher under the IC system than under MC, whereas faba bean yield as fresh seeds did not differ. The land equivalent ratio was 1.06, showing that improved yield under IC resulted from efficient land resource use. Even though MC cabbage had the highest aboveground biomass, total N accumulation was higher under IC and MC faba bean systems. Both root frequency and intensity were greater under IC faba bean rows compared with MC faba bean because of the presence of cabbage roots in faba bean rows. Monocropped cabbage had the highest root intensity and the lowest amount of soil mineral N in the 0–1.5 m depth after harvest. Monocropped cabbage was efficient in assimilating N, whereas MC faba bean was efficient in exporting N as harvestable yield. The nitrogen use efficiency using the IC system (75%) was higher than growing faba bean (44%) and cabbage (65%) alone. Thus, faba bean as an intercrop in organic cabbage production systems improves land and N use efficiency by complementary root growth.     

Effects of intercropping and Rhizobium inoculation on yield and rhizosphere bacterial community of faba bean (Vicia faba L.)

The effects of intercropping with maize and Rhizobium inoculation on the yield of faba bean and rhizosphere bacterial diversity were analyzed by terminal restriction fragment length polymorphism, amplified 16S rDNA restriction analysis (ARDRA), and 16S rDNA sequencing. The results showed that intercropping but not Rhizobium inoculation significantly increased the faba bean yield. Probably the relatively high level of native rhizobia in soil annulled the effect of rhizobia inoculation. ARDRA results showed that intercropping did not affect bacterial diversity whereas Rhizobium inoculation decreased bacterial diversity. The canonical correspondence analysis showed that the composition of bacterial community was changed apparently by intercropping, and there was a positive correlation (P = 0.724) between faba bean yields and intercropping and an apparent correlation (P = 0.648) between intercropping and total N. The available content of K and P had a lower effect on the bacterial community composition than did the total N content, Rhizobium inoculation, and microbial biomass C. Rhizobium inoculation negatively correlated with microbial biomass C (P = −0.827). These results revealed a complex interaction among the intercropped crops, inoculation with rhizobia, and indigenous bacteria and implied that the increase of faba bean production in intercropping might be related to the modification of rhizosphere bacterial community.     

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.     

Intra‐specific variation for salt tolerance in a potential oil‐seed crop,brown mustard (Brassica juncea (l.) Czern. and Coss.)

Thirty eight accessions of brown mustard (Brassica juncea (L.) Czern. and Coss.) were screened after two weeks growth in solution culture containing 120 mol m‐³ NaCl. Considerable variation for salt tolerance was observed in this set of germplasm, since some accessions showed relatively vigorous growth in saline medium.

In order to determine the consistency of degree of salt tolerance at different growth stages of crop life cycle two salt tolerant accessions, P‐15 and KS‐51 and two salt sensitive 85362 and 85605 were tested at the adult stage in 0(control), 100 and 200 mol m^‐3 NaCl. Both the tolerant accessions produced significantly greater fresh and dry biomass and had considerably higher seed yield than those of the salt sensitive accessions. Analysis of different ions in the leaves showed that salt tolerant accessions contained greater amounts of Na⁺, K⁺ and Ca²⁺ than the salt sensitive accessions, although they did not differ significantly for leaf Cl^‐. Only one salt tolerant accession P‐15 had greater leaf K/Na ratio and K⁺ versus Na⁺ selectivity compared with the tolerant KS‐51 and the two salt sensitive accessions.

From this study it was established that there is a considerable variation for salt tolerance in B.juncea which can be exploited by selection and breeding for improvement of its salt tolerance. Since the degree of salt tolerance in B.juncea does not change at different growth stages of the crop life cycle, selection for salt tolerance at the initial growth stages could provide individuals that would be tolerant at all other growth stages. Accumulation of Na⁺, K⁺ and Ca²⁺ in the leaves are important components of salt tolerance in B.juncea.     

RESPONSES OF COOL-SEASON GRAIN LEGUMES AND WHEAT TO SOIL-APPLIED ZINC

The yield and zinc (Zn) content response of faba bean (Vicia faba L.), chickpea (Cicer arietinum L.), lentil (Lens culinaris Medik.) and wheat (Triticum aestivum L.) to applications of Zn fertilizer was compared in a glasshouse experiment using two alkaline soils from southwestern Australia. Comparative Zn requirements were determined from yields of 46-day-old dried shoots when no Zn fertilizer was applied, the amount of Zn required to produce the same percentage of the maximum (relative) yield of dried shoots, and the Zn content of dried shoots (Zn concentration multiplied by yield of dried shoots). The concentration of Zn in youngest tissue and in dried shoots was used to determine critical concentrations for Zn in tissue. Faba bean used indigenous soil Zn more effectively than chickpea, followed by wheat and then lentil. The Zn requirement was lowest for faba bean, and increased in the order faba bean < chickpea < wheat < lentil. Zinc concentration in dried youngest tissue and in dried shoots increased with an increase in the amount of added Zn. The critical Zn concentration in the youngest tissue, associated with 90% of the relative yield, was (mg Zn kg^?1): 25 for lentil, 18 for faba bean, 17 for chickpea and 12 for wheat; corresponding values for dried whole tops (mg Zn kg^?1) were: 30 for lentil, 19 for faba bean, 17 for chickpea, and 20 for wheat. Information on comparative responses of the grain legumes to Zn additions relative to wheat, and critical tissue test values, will aid in the fertilizer management of Zn in cool-season grain legumes in the southwestern Australian farming systems.     

Evaluation of European maize (<Emphasis Type="Italic">Zea mays</Emphasis> L.) germplasm under cold conditions

Maize (Zea mays L.) is a tropical crop with low tolerance to cold conditions and has to be planted late in temperate areas due to low temperatures. The objective of this research was to identify new cold tolerant populations among the European germplasm useful for improving adaptation to early sowing. For that, the European Union Maize Landraces Core Collection (EUMLCC) was evaluated under cold conditions. After a preliminary screening of 95 populations the 11 populations with best germination and early growth under cold conditions were multiplied and evaluated in a cold chamber and in early field sowings at two locations during 2 years. The cold tolerant populations from the EUMLCC were not significantly different from the cold tolerant checks in the cold chamber. In early field sowing, some EUMLCC populations had similar emergence than the commercial checks and the coldest tolerant hybrids, and higher vigor than all the hybrids and the yield of some of the populations surpassed the yield of the cold tolerant hybrids. Altogether, Aranga1 emerged as the most promising candidate as base population for improving adaptation to early sowing.     

Growth,P uptake in grain legumes and changes in rhizosphere soil P pools

In soils with low P availability, several legumes have been shown to mobilise less labile P pools and a greater capacity to take up P than cereals. But there is little information about the size of various soil P pools in the rhizosphere of legumes in soil fertilised with P although P fertiliser is often added to legumes to improve N₂ fixation. The aim of this study was to compare the growth, P uptake and the changes in rhizosphere soil P pools in five grain legumes in a soil with added P. Nodulated chickpea (Cicer arietinum L.), faba bean (Vicia faba L.), white lupin (Lupinus albus L.), yellow lupin (Lupinus luteus L.) and narrow-leafed lupin (Lupinus angustifolius L.) were grown in a loamy sand soil low in available P to which 80 mg P kg⁻¹ was added and harvested at flowering and maturity. At maturity, growth and P uptake decreased in the following order: faba bean > chickpea > narrow-leafed lupin > yellow lupin > white lupin. Compared to the unplanted soil, the depletion of labile P pools (resin P and NaHCO₃-P inorganic) was greatest in the rhizosphere of faba bean (54% and 39%). Of the less labile P pools, NaOH-P inorganic was depleted in the rhizosphere of faba bean while NaOH-P organic and residual P were most strongly depleted in the rhizosphere of white lupin. The results suggest that even in the presence of labile P, less labile P pools may be depleted in the rhizosphere of some legumes.     

Wheat response to N2 fixed by faba bean (Vicia faba L.) as affected by sulfur fertilization and rhizobial inoculation in semi‐arid Northern Ethiopia

Nitrogen fixation in faba bean (Vicia faba cv. Mesay) as affected by sulfur (S) fertilization (30 kg S ha^–1) and inoculation under the semi‐arid conditions of Ethiopia was studied using the ¹⁵N‐isotope dilution method. The effect of faba bean–fixed nitrogen (N) on yield of the subsequent wheat crop (Triticum aestivum L.) was also assessed. Sulfur fertilization and inoculation significantly (p < 0.05) affected nodulation at late flowering stage for both 2004 and 2005 cropping seasons. The nodule number and nodule fresh weighs were increased by 53% and 95%, relative to the control. Similarly, both treatments (S fertilization and inoculants) significantly improved biomass and grain yield of faba bean on average by 2.2 and 1.2 Mg ha^–1. This corresponds to 37% and 50% increases, respectively, relative to the control. Total N and S uptake of grains was significantly higher by 59.6 and 3.3 kg ha^–1, which are 76% and 66% increases, respectively. Sulfur and inoculation enhanced the percentage of N derived from the atmosphere in the whole plant of faba bean from 51% to 73%. This corresponds to N₂ fixation varying from 49 to 147 kg N ha^–1. The percentage of N derived from fertilizer (%Ndff) and soil (%Ndfs) of faba bean varied from 4.3% to 2.8 %, and from 45.1% to 24.0%, corresponding to the average values of 5.1 and 47.9 kg N ha^–1. Similarly, the %Ndff and %Ndfs of the reference crop, barley, varied from 8.5 % to 10.8% and from 91.5% to 89.2%, with average N yields of 9.2 and 84.3 kg N ha^–1. Soil N balance after faba bean ranged from 13 to 52 kg N ha^–1. Beneficial effects of faba bean on yield of a wheat crop grown after faba bean were highly significant, increasing the average grain and N yields of this crop by 1.11 Mg ha^–1 and 30 kg ha^–1, relative to the yield of wheat grown after the reference crop, barley. Thus, it can be concluded that faba bean can be grown as an alternative crop to fallow, benefiting farmers economically and increasing the soil fertility.     

Evaluating landraces of bread wheat <Emphasis Type="Italic">Triticum aestivum</Emphasis> L. for tolerance to aluminium under low pH conditions

Bread wheat (Triticum aestivum L.) landraces held within ex situ collections offer a valuable and largely unexplored genetic resource for wheat improvement programs. To maximise full utilisation of such collections the evaluation of landrace accessions for traits of interest is required. In this study, 250 accessions from 21 countries were screened sequentially for tolerance to aluminium (Al) using haematoxylin staining of root tips and by root regrowth measurement. The staining test indicated tolerance in 35 accessions, with an intermediate response to Al exhibited in a further 21 accessions. Of the 35 accessions classified as tolerant, 33 also exhibited increased root length following exposure to Al. The tolerant genotypes originated from Bulgaria, Croatia, India, Italy, Nepal, Spain, Tunisia, and Turkey. AFLP analysis of the 35 tolerant accessions indicated that these represent diverse genetic backgrounds. These accessions form a valuable set of germplasm for the study of Al tolerance and may be of benefit to breeding programs for expanding the diversity of the gene pool from which tolerant cultivars are developed.