Cengiz Toker

Legume Crops Phylogeny and Genetic Diversity for Science and Breeding

Economically, legumes (Fabaceae) represent the second most important family of crop plants after the grass family, Poaceae. Grain legumes account for 27% of world crop production and provide 33% of the dietary protein consumed by humans, while pasture and forage legumes provide vital part of animal feed. Fabaceae, the third largest family of flowering plants, has traditionally been divided into the following three subfamilies: Caesalpinioideae, Mimosoideae, and Papilionoideae, all together with 800 genera and 20,000 species. The latter subfamily contains most of the major cultivated food and feed crops. Among the grain legumes are some of mankinds earliest crop plants, whose domestication parallelled that of cereals: Soybean in China; faba bean, lentil, chickpea and pea in the Fertile Crescent of the Near East; cowpeas and bambara groundnut in Africa; soybean and mungbeans in East Asia; pigeonpea and the grams in South Asia; and common bean, lima bean, scarlet runner bean, tepary bean and lupin in Central and South America. The importance of legumes is evidenced by their high representation in ex situ germplasm collections, with more than 1,000,000 accessions worldwide. A detailed knowledge of the phylogenetic relationships of the Fabaceae is essential for understanding the origin and diversification of this economically and ecologically important family of angiosperms. This review aims to combine the phylogenetic and genetic diversity approaches to better illustrate the origin, domestication history and preserved germplasm of major legume crops from 13 genera of six tribes and to indicate further potential both for science and agriculture.

A note on the evolution of kabuli chickpeas as shown by induced mutations in Cicer reticulatum Ladizinsky

Two distinct chickpeas of the domestic chickpea, C. arietinum L., exist and are referred to as ‘desi’ or microsperma and ‘kabuli’ or macrosperma. Cicer reticulatum Ladiz. is considered to be the wild progenitor of the domestic chickpea. However, the morphological variation in 18 original accessions of C. reticulatum is narrower than those of the domestic chickpeas. The aim of the study is to increase the variability in C. reticulatum. In M2 generation, a mutant with white flower color was isolated despite of the fact that the parent has the pink flower. Although seed coat color of the parent was dark brown, the mutant was cream like ‘kabuli’ chickpea. It is commonly accepted that the large seeded domestic ‘kabuli’ chickpeas originated from the small seeded ‘desi’ chickpeas, but the induced mutants (white flower and cream seed coat color) of C. reticulatum may suggest an additional path for the evolution of ‘kabuli’ chickpea. ‘Kabuli’ chickpeas could have originated from spontaneous mutants of C. reticulatum. In M3 generation, multipinnate leaf, erect growth habit, green seed and double-podded chickpeas were isolated. Among these progenies, morphologic variability increased and approached domesticated chickpea. Based on historical records and the induced mutants obtained from this study, the domestic ‘kabuli’ chickpea could have directly emerged from C. reticulatum in ancient Eastern Turkey.

Preliminary screening and selection for cold tolerance in annual wild Cicer 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.

Evaluation of annual wild Cicer 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.

Estimation of Outcrossing Rate in Chickpea (Cicer Arietinum L.) Sown in Autumn

Gene flow via outcrossing from transgenic plants to relatives will be one of the most important concerns to grow of the transgenic chickpea (Cicer arietinum L.) in European Union (EU). This report is therefore focused on spontaneous outcrossing rate in chickpea. A total of 39 kabuli type mutants with white flower and one desi type with pink flower were grown to estimate spontaneous outcrossing rate. Outcrossing rate ranged from 0.0 to 1.25% in mutant materials. Since labelling threshold for transgenic contamination in food and feed in European Union (EU) is 0.9%, outcrossing rate of 1.25% is higher than threshold of 0.9% in EU, and this result suggests that cultivation of transgenic chickpea will be under high risk to be contaminated chickpeas in neighbourhood fields.

Evaluation of yield criteria with phenotypic correlations and factor analysis in chickpea

Factor analysis is a statistical technique for reducing a large number of correlated variables to a small number of main factors. This investigation was undertaken to evaluate yield criteria in chickpea using phenotypic correlations and factor analysis. The total factors explained 87% of the total variance in the characters studied. Factor 1 comprised seed yield, biological yield and number of pods per plant. In addition, the biological yield and number of pods per plant were significantly correlated with seed yield. Therefore, biological yield and number of pods per plant should be evaluated in selection to increase the seed yield in chickpea breeding programmes. Factor 2 consisted of days to flowering and flowering duration. There was significantly negative correlation between days to flowering and flowering duration. Earliness should be considered alongside flowering duration. Factor 3 encompassed plant height and first pod height. Correlation between first pod height and plant height was significantly positive. Higher first pod height should be selected because of importance of plant height at harvest. The final factor was seed weight. Seed weight should be evaluated solely for selection of large seeded genotypes.

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.

Comparison of expressivity and penetrance of the double podding trait and yield components based on reciprocal crosses of kabuli and desi chickpeas ( Cicer arietinum L.)

Double podding in cultivated chickpeas (Cicer arietinum L.) can increase yield and yield stability. In the present study, we performed reciprocal crosses of ‘kabuli’ (double podded) and ‘desi’ (single podded) chickpeas to determine (i) the expressivity and penetrance of double podding, (ii) the correlations of yield and yield components, and (iii) the heritability of double podding, flower color, and stem pigmentation in F2 plants. Reciprocal crosses were performed with two genotypes, AC 2969 (kabuli) and ICC 4969 (desi), to generate F1 and F2 plants. The results indicated hybrid vigor (heterosis) for yield in F1 plants and better performance of F2 plants. Yield and yield components of some lines in F2 were superior to the best parent, indicative of transgressive segregation. In particular, the presence of double podding (‘s’ allele) significantly increased yield in some of the transgressive segregants. Expressivity and penetrance of the ‘s’ allele depends on the background of the female parent. Some of the double podding progeny had greater seed yields than those of the single podding progeny and greater seed yields than the best parents. Double podding, stem pigmentation, and pink flowers each appears to be governed by a single recessive gene. Stem pigmentation and pink flowers appear to be linked traits that depend on the genetic background of the crossed chickpeas. Taken together, our studies of reciprocal crosses of kabuli and desi chickpeas clearly showed that yield could be improved by selection for transgressive phenotypes that have double podding.

Screening and selection of faba beans (Vicia faba L.) for cold tolerance and comparison to wild relatives

Since autumn-sown faba beans possess several advantages including higher seed yield over the spring cultivars, the study was aimed to screen and select cold tolerant accessions of faba beans (Vicia faba L.) and compare these to wild species in the highland of the west Mediterranean region, Turkey. A total of 114 accessions of Vicia species including 109 accessions of faba bean, three accessions of narbon bean (V. narbonensis L.) and two accessions of V. montbretii Fisch. et C.A. Mey. were screened for cold tolerance at seedling stage in two successive years, 2005–2006 and 2006–2007 growth seasons. Accessions were evaluated for cold tolerance using a 1 (Highly cold tolerant)-5 (Highly cold susceptible) visual scale. Considerable variation was found for cold tolerance and some agronomical characteristics in faba beans. Wild relatives of faba bean were found to be more tolerant to cold than those of cultivated faba beans. Although some pigmented accessions were free from freezing damage at −9.6°C without snow cover, accessions with white flowers were damaged. The proposed screening technique could easily be used to evaluate many faba bean accessions for cold tolerance. To increase yield, it was concluded that the cold tolerant accessions with high yield could be grown as autumn-sown crop in the target environment.

Endogenous Hormone Variations in Annual Wild Cicer Species

All processes that regulate of growth, differentiation and development and also stomatal movement are influenced by endogenous hormones in plants. Research related with endogenous hormones is known for cultivated chickpea (Cicer arietinum L.), while in wild chickpeas no data existed. In this study, C. bijugum K.H. Rech.; C. chorassanicum (Bge) M. Pop.; C. cuneatum Hochst. ex Rich.; C. echinospermum P.H. Davis; C. judaicum Boiss.; C. pinnatifidum Jaub. et Sp.; C. reticulatum Ladiz.; and C. yamashitae Kitamura were evaluated for variations in endogenous plant hormone concentrations; indole-3-acetic acid, zeatin, gibberellic acid, and abscisic acid in both leaf and pod. It was concluded that there was a great variation on endogenous plant hormones among the annual wild Cicer species. The data may support selection for various attributes.