Allelic relationships of genes controlling number of flowers per axis in chickpea

Genetic variation for number of flowers per axis in chickpea (Cicer arietinum L.) includes single-flower, double-flower, triple-flower and multi-flower traits. A double-flowered (DF) line ICC 4929, a triple-flowered (TF) line IPC 99-18 and a multi-flowered (MF) line JGM 7 were intercrossed in all possible combinations and flowering behavior of parents, F₁s and F₂s was studied to establish allelic relationships, penetrance and expressivity of genes controlling number of flowers per axis in chickpea. The F₁ from ICC 4929 (DF) × IPC 99-18 (TF) cross were double-flowered, whereas F₁ from ICC 4929 (DF) × JGM 7 (MF) and IPC 99-18 (TF) × JGM 7 (MF) crosses were single-flowered. The F₂ from ICC 4929 (DF) × IPC 99-18 (TF) cross gave a good fit to a 3:1 ratio for double-flowered and triple-flowered plants. The F₂ from ICC 4929 (DF) × JGM 7 (MF) cross segregated in a ratio of 9:3:3:1 for single-flowered, double-flowered, multi-flowered and double-multi-flowered plants. The F₂ from IPC 99-18 (TF) × JGM 7 (MF) cross segregated in a ratio of 9:3:4 for single-flowered, triple-flowered and multi-flowered plants. The results clearly established that two loci control number of flowers per axis in chickpea. The double-flower and triple-flower traits are controlled by a single-locus (Sfl) and the allele for double-flowered trait (sfl ^d ) is dominant over the allele for triple-flower trait (sfl ^t ). The three alleles at the Sfl locus has the dominance relationship Sfl > sfl ^d > sfl ^t . The multi-flower trait is controlled by a different gene (cym). Single-flowered plants have dominant alleles at both the loci (Sfl_ Cym_). The double-flower, the triple-flower and the multi-flower traits showed complete penetrance, but variable expressivity. The expressivity was 96.3% for double-flower and 76.4% for double-pod in ICC 4929, 81.2% for triple-flower and 0.0% for triple-pod in IPC 99-18, and 51.3% for multi-flower and 24.7% for multi-pod in JGM 7. Average number of flowers per axis and average number of pods per axis were higher in JGM 7 than double-flowered line ICC 4929 and triple-flowered line IPC 99-18. The results of this study will help in development of breeding strategies for exploitation of these flowering and podding traits in chickpea improvement.     

Broad-few-leaflets and outwardly curved wings: two new mutants of chickpea

This study was aimed at the induction of morphological mutations for increasing genetic variability and making available additional genetic markers for linkage studies in chickpea (Cicer arietinum L.). A wilt‐resistant, well‐adapted chickpea cultivar of central India,‘JG 315’(Jawahar gram 315), was used for the induction of mutations. Seeds presoaked in distilled water for 2 h were treated with ethyl methane sulphonate (EMS) using six different concentrations (0.1, 0.2, 0.3, 0.4, 0.5 and 0.6%) and two different durations (6 and 8 h). Several morphological mutants were identified in M₂. One of the mutants, isolated from a treatment of 0.3% EMS for 8 h, had five to nine large leaflets per leaf in comparison with 11‐17 normal‐sized leaflets per leaf observed in the parental cultivar ‘JG 315′. The mutant was designated broad‐few‐leaflets. Many leaves of this mutant showed a cluster of three to five overlapping leaflets at the terminal end. The other mutant, designated outwardly curved wings, was isolated from the 0.5% EMS treatment for 6 h. In this mutant, the wings were curved outwards, exposing the keel petal, while the wings in typical chickpea flowers are incurved and enclose the keel. The lines developed from the broad‐few‐leaflets and outwardly curved wings mutants were named JGM 4 (Jawahar gram mutant 4) and JGM 5, respectively. Inheritance studies indicated that each of these mutant traits is governed by a single recessive gene. The gene for broad‐few‐leaflets was designated bfl and the gene for outwardly curved wings was designated ocw. The locus bfl was found to be linked with the locus lg (light green foliage) with a map distance of 18.7 ± 6.3 cM.     

Allelic relationship between spontaneous and induced mutant genes for stem fasciation in chickpea

Stem fasciation is a morphological abnormality observed in plants where the stem is widened and leaves and flowers or pods are clustered at the apex. Several spontaneous mutants and one induced mutant for stem fasciation are found in chickpea (Cicer arietinum L.). This study was aimed at determining allelic relationship between spontaneous and induced mutant genes controlling stem fasciation and effects of stem fasciation on grain yield. Two spontaneous (ICC 2042 and ICC 5645) and one induced (JGM 2) stem fasciation mutants were crossed in all combinations, excluding reciprocals. The F₁ and F₂ plants from a cross between the two spontaneous mutants had fasciated stem. This indicated the presence of a common gene (designated fas1) for stem fasciation in the two spontaneous mutants. The F₁s of the crosses of the induced mutant JGM 2 with both spontaneous mutants had normal plants and segregated in a ratio of 9 normal : 7 fasciated plants in F₂. Thus, the gene for stem fasciation in the induced mutant JGM 2 (designated fas2) is not allelic to the common gene for stem fasciation in spontaneous mutants. The two genes in dominant condition produced normal non‐fasciated stem. The fasciated and the non‐fasciated F₂ plants did not differ significantly for number of pods per plant, number of seeds per plant, grain yield per plant and seed size, suggesting that it is possible to exploit the fasciated trait in chickpea breeding without compromising on yield.     

Diallel analyses reveal the genetic control of resistance to ascochyta blight in diverse chickpea and wild Cicer species

Ascochyta blight is a major fungal disease affecting chickpea production worldwide. The genetics of ascochyta blight resistance was studied in five 5 × 5 half-diallel cross sets involving seven genotypes of chickpea (ICC 3996, Almaz, Lasseter, Kaniva, 24B-Isoline, IG 9337 and Kimberley Large), three accessions of Cicer reticulatum (ILWC 118, ILWC 139 and ILWC 184) and one accession of C. echinospermum (ILWC 181) under field conditions. Both F₁ and F₂ generations were used in the diallel analysis. The disease was rated in the field using a 1–9 scale. Almaz, ICC 3996 and ILWC 118 were the most resistant (rated 3–4) and all other genotypes were susceptible (rated 6–9) to ascochyta blight. Estimates of genetic parameters, following Hayman’s method, showed significant additive and dominant gene actions. The analysis also revealed the involvement of both major and minor genes. Susceptibility was dominant over resistance to ascochyta blight. The recessive alleles were concentrated in the two resistant chickpea parents ICC 3996 and Almaz, and one C. reticulatum genotype ILWC 118. The wild Cicer accessions may have different major or minor resistant genes compared to the cultivated chickpea. High narrow-sense heritability (ranging from 82% to 86% for F₁ generations, and 43% to 63% for F₂ generations) indicates that additive gene effects were more important than non-additive gene effects in the inheritance of the trait and greater genetic gain can be achieved in the breeding of resistant chickpea cultivars by using carefully selected parental genotypes.     

Inheritance of resistance to Botrytis cinerea Pers. in Cicer arietinum L.

Summary Chickpea (Cicer arietinum L.) line ICC 1069 was selected as resistant parent after screening for resistance to grey mould (Botrytis cinerea Pers.) under artificial inoculation conditions. It was crossed with four high yielding susceptible varieties of chickpea. Crosses ICC 1069 × BGM 413 and ICC 1069 × BG 256 showed monogenic dominant resistance in ratio of 3R (resistant): 1S (susceptible). However, in crosses, ICC 1069 × BGM 419 and ICC 1069 × BGM 408, a ratio of 13S (susceptible) : 3R (resistant) was obtained indicating the presence of epistatic interaction. The results pointed towards the presence of a type of major gene resistance to grey mould in chickpea.     

A gene producing one to nine flowers per flowering node in chickpea

Chickpea (Cicer arietinum L.) has a racemose type of inflorescence and at each axis of the raceme usually one or two and rarely three flowers are borne. Plants producing 3 to 9 flowers, arranged in acymose inflorescence, at many axis of the raceme, were identified in F₂ of an interspecific cross ICC 5783 (C. arietinum) × ICCW 9 (C. reticulatum)in which both the parents involved were single-flowered. A spontaneous mutation in one of the two parents or in the F₁was suspected. However, the possibility for establishment of a rare recombination of two interacting recessive genes could not be ruled out. The number of pods set varied from 0 to 5 in each cyme. Inheritance studies indicated that a single recessive gene, designated cym, is responsible for cymose inflorescence. The allelic relationship of cym with sfl, a gene for double-flowered trait, was studied from a cross involving multi flowered plants and the double-flowered line ICC 4929. Thecym gene was not allelic to sfl, suggesting that two loci control the number of flowers per peduncle in chickpea. The cym locus segregated independently of the locus sfl, ifc (inhibitor of flower color) and blv (bronze leave). This revised version was published online in August 2006 with corrections to the Cover Date.     

Induction and inheritance of determinate growth habit in chickpea (Cicer arietinum L.)

Summary The character of determinate plant growth has not been reported for chickpea and has not been observed in the world germplasm collection at ICRISAT, Patancheru, India. A determinate growth habit would be desirable where growing conditions often lead to excessive vegetative growth. We attempted to generate this trait by mutation breeding. Seeds of the cultivar ICCV 6 were exposed to varying irradiation treatments, M₁ and M₂ populations were raised, and in the latter one plant was detected that showed the determinate growth habit and female sterility. The character of determinate growth segregated in a postulated digenic epistatic 3:13 fashion in the F₂ and confirmed its digenic mode of inheritance in the F₃ and F₄. The symbol cd is proposed for the allele conditioning for determinancy and Dt for the allele expressing the determinate trait. Continued mutation breeding with this and other material may result in identifying fully fertile, determinate plant types.Abbreviations DT - determinate - IDT - indeterminate ICRISAT Journal Article No. 1396.     

Genetic basis of pod borer (Helicoverpa armigera) resistance and grain yield in desi and Kabuli Chickpea (Cicer arietinum L.) under unprotected conditions

A series of half-diallel crosses involving early, medium and late maturity desi and kabuli type chickpea (Cicer arietinum L.) genotypes with stable resistance to Helicoverpa pod borer, along with the parents, were evaluated at two locations in India to understand the inheritance of pod borer resistance and grain yield. Inheritance of resistance to pod borer and grain yield was different in desi and kabuli types. In desi type chickpea, the additive component of genetic variance was important in early maturity and dominance component was predominant in medium maturity group, while in the late maturity group, additive as well as dominance components were equally important in the inheritance of pod borer resistance. Both dominant and recessive genes conferring pod borer resistance seemed equally frequent in the desi type parental lines of medium maturity group. However, dominant genes were in overall excess in the parents of early and late maturity groups. In the kabuli medium maturity group, parents appeared to be genetically similar, possibly due to dispersion of genes conferring pod borer resistance and susceptibility, while their F₁s were significantly different for pod borer damage. The association of genes conferring pod borer resistance and susceptibility in the parents could be attributed to the similarity of parents as well as their F₁s for pod borer damage in kabuli early and late maturity groups. Grain yield was predominantly under the control of dominant gene action irrespective of the maturity groups in desi chickpea. In all the maturity groups, dominant and recessive genes were in equal frequency among the desi parental lines. Dominant genes, which tend to increase or decrease grain yield are more or less present in equal frequency in parents of the early maturity group, while in medium and late maturity groups, they were comparatively in unequal frequency in desi type. Unlike in desi chickpea, differential patterns of genetic components were observed in kabuli chickpea. While the dominant genetic component was important in early and late maturity group, additive gene action was involved in the inheritance of grain yield in medium duration group in kabuli chickpea. The dominant and recessive genes controlling grain yield are asymmetrically distributed in early and medium maturity groups in kabuli chickpea. The implications of the inheritance pattern of pod borer resistance and grain yield are discussed in the context of strategies to enhance pod borer resistance and grain yield in desi and kabuli chickpea cultivars.     

Fasciation in chickpea: genetics and evaluation

Summary A spontaneous fasciated mutant was detected in the chickpea cv. Amethyst. It was characterised by broad, strap-like stems, irregular leaf arrangement and clustering of pods towards the stem apices. F₂ and F₃ segregations showed that fasciation was controlled by a single, recessive gene for which the symbol fas is proposed. Field trials comparing the fasciated mutant with its non-fasciated isoline showed that fasciation was associated with lower yield, larger seeds, delayed flowering and increased lodging.     

Resistance to Ascochyta blight in chickpea - Genetic basis

Summary Genetic regulation of host resistance in chickpea-Ascochyta rabiei interaction system is governed by two dominant complementary genes each in the genotypes GLG 84038 and GL 84099, whereas the resistance in a black seeded genotype ICC 1468 was controlled by one dominant and one recessive independent gene. In all the genotypes, resistance is operated by inter-allelic interactions. The genes conferring resistance in GLG 84038 were found to be different to those operating in GL 84099 and ICC 1468. Among the five dominant genes dispersed in 3 genotypes under study, at least one has been reported for the first time, as to date, only three dominant genes have been reported in the literature.The four identified dominant genes in GLG 84038 and GL 84099 have been named as Arc₁, Arc₂ (in GLG 84038) and Arc₃, Arc₄ (in GL 84099). The undistinguished dominant gene in ICC 1468 has been named as Arc_5(3,4) as it could not be equated or differentiated from Arc₃ or Arc₄. The recessive gene in ICC 1468 has been named as Arc₁.Generation mean analysis of the 6 resistant × susceptible crosses involving the same genotypes, revealed that the genes conferring resistance in any of the 3 genotypes did not follow simple Mendelian inheritance but were influenced by inter allelic interactions. Additive gene effect along with dominance were operative in all the 3 genotypes under study in conferring resistance. However, the mechanism of resistance in GLG 84038 and GL 84099 were primarily additive in nature while that in ICC 1468, dominance as well as dominance × dominance interactions were more important than additive gene action.     

Morphology and genetics of a new found determinate genotype in chickpea

Chickpea (Cicer arietinum L.) is an indeterminate plant and produce excessive vegetative growth that acts as a competitive sink for developing pods resulting in reduced fruit set whenever soil moisture and temperature conditions are favorable. Determinate genotype was so far not available in the world chickpea germplasm. Determinate chickpea is needed to change its plant architecture in order to achieve a breakthrough in its productivity and stabilize yields in cool and long-season sub-tropical environments of semi-arid tropics. A true breeding determinate chickpea genotype was developed for the first time in the breeding programme. The objectives were to study: (i) the new found determinate genotype BGD 9971 for important plant characteristics and (ii) the genetics of determinate growth habit in it. Determinate genotype was bushy, compact and dwarf in its morphology; the stem growth terminated by a flower and produced 1–4 seeds per pod. The segregation patterns in the F₂ and F₃ of the two crosses (BGD 72 × BGD 9971 and BGD 128 × BGD 9971) involving indeterminate and determinate parents have shown that the determinate growth habit in BGD 9971 was governed by two recessive genes. The genes for determinacy in BGD 9971 were designated as dt1 and dt2. The homozygous recessive for both alleles (dt1dt1dt2dt2) produced a determinate phenotype. The utilization of genes identified for determinacy in the newly developed BGD 9971 has the major impact on chickpea breeding for better adaptation to cool climate, high fertility and irrigated environments.     

Introgression of resistance to late blight (Phytophthora infestans) from Solanum pinnatisectum into S. tuberosum using embryo rescue and double pollination

In order to investigate the agricultural potential of the genus Vicia, and identify traits associated with productivity and responsiveness to environment, 34 undomesticated Mediterranean accessions representing Section Narbonensis (V. johannis, V. narbonensis) and V. sativa were grown in five contrasting environments in northern Syria (growing season rainfall: 76–290 mm).Highly significant genotype × environment interactions were observed for all traits. For most of the components of yield, accession mean performance (productivity)was highly correlated with responsiveness across environments (r = 0.59–0.96), as defined by joint linear regressions. Thus high yielding genotypes tended to be relatively more productive than low yielding genotypes under conditions that favoured high yields. Regression analysis revealed that mean site yields were positively correlated to rainfall (r = 0.85) and its attendant effect on growing season length as measured by cumulative season temperature and phenology (r = 0.59–0.81).In order to examine yield related traits independently of taxonomy, genotypes were grouped into three categories using K-means clustering based on productivity and responsiveness of seed, hay and biological yield. Highly productive/responsive genotypes were tall with high harvest index, large seeds and low fecundity (seeds and pods per plant), whereas unproductive/unresponsive plants tended to be short, highly fecund, with small seeds and low harvest index. Principal components analysis showed that responsiveness, in terms of seed, hay and biological yields, was closely related to phenological plasticity. Thus highly productive/responsive genotypes were able to start flowering earlier than unproductive/unresponsive genotypes in early environments, but significantly later in late, higher rainfall environments. Plant growth habit was also related to yield responsiveness. In environments with little biomass production the proportion of erect plants was high in all three categories. In more favourable, high biomass environments, the proportion of erect plants in unproductive/unresponsive genotypes fell dramatically, but was unchanged among productive/responsive genotypes. We suggest that for unproductive/unresponsive genotypes competition for light is increased under optimal growth conditions. We argue that the optimal combination of fixed and responsive traits in high yielding genotypes results in a `compound interest-type' response to more favourable environments. Highly productive and responsive genotypes can capture resources more effectively than their low yielding counterparts, leading to a positive relationship between performance and responsiveness for most components of yield. Differences in productivity and responsiveness for seed, hay and biological yield reflected Vicia taxonomy, increasing in the following order from low to high: V. johannis, V. sativa, the small seeded V. narbonensis (salmonea, jordanica, affinis) V. n. var. narbonensis, and finally V. n. var.aegyptiaca. V. n. var. aegyptiaca showed the most agricultural potential, since the taxon contained all the properties of productive/responsive genotypes listed above, yielding >1 t/ha under extremely arid conditions (104 mm),and >2.5 t/ha on 290 mm rainfall, confirming its potential for dry environments. This revised version was published online in August 2006 with corrections to the Cover Date.     

Induction,genetics and possible use of glabrousness in chickpea

Summary A giabrous mutant was identified from progenies of chickpea seeds that were treated with ethyl methane sulphonate (EMS). The mutant has no shoot hairs in contrast to the dense hairs on normal chickpeas. The character is governed by a single recessive gene. This mutant can be useful in certain pathological and eniomological studies.     

Comparison of recurrent and congruity backcrossing for interracial hybridization in common bean

Summary Two common bean (Phaseolus vulgaris L.) cultivars were used for recurrent backcrossing (i.e., repeated backcrossing to one of the parents) to both parents independently and for congruity backcrossing (i.e., backcrossing alternately to both parents). One cultivar, ICA Pijao of race Mesoamerica, was late maturing, with erect type II growth habit and small seeds. The other was Pinto UI 114 of race Durango, an early maturing cultivar with prostrate type III growth habit and medium seeds. One to three recurrent backcrosses (RBC) to both parents, and two rounds of congruity backcrosses (CBC), were made. Thirty-two random lines from each method along with two parents were compared in a reps-in-set design at two locations (Popayán and Quilichao) in Colombia in 1992–1993.Differences between lines derived through different methods were found for seed yield, 100-seed weight, days to maturity, growth habit, and seed color pattern. The RBC to ICA Pijao produced lines with relatively higher seed yield, smaller seed size, and delayed maturity. Similarly, the RBC to Pinto UI 114 produced lines with reduced yield, medium seed size, and earlier maturity. All lines from one, two, and three RBC to Pinto UI 114 had type III growth habit. While most lines from the RBC to ICA Pijao had erect type II Growth habit, a few type III lines were also found in all the RBC. The lines derived from the CBC mostly possessed yield, maturity, and seed characteristics between those of the two parents and lines derived from RBC to both parents independently. They also had more variation for growth habit. To maximize recombination between and retention of desirable traits from distantly related parents used in interracial crosses, use of the CBC is suggested.     

Mapping genes for double podding and other morphological traits in chickpea

Seed traits are important considerations for improving yield and product quality of chickpea (Cicer arietinum L.). The purpose of this study was to construct an intraspecific genetic linkage map and determine map positions of genes that confer double podding and seed traits using a population of 76 F₁₀ derived recombinant inbred lines (RILs) from the cross of ‘ICCV-2’ (large seeds and single pods) × ‘JG-62’ (small seeds and double podded). We used 55 sequence-tagged microsatellite sites (STMS), 20 random amplified polymorphic DNAs (RAPDs), 3inter-simple sequence repeats (ISSR) and 2 phenotypic markers to develop a genetic map that comprised 14 linkage groups covering297.5 cM. The gene for double podding (s) was mapped to linkage group 6 and linked to Tr44 and Tr35 at a distance of7.8 cM and 11.5 cM, respectively. The major gene for pigmentation, C, was mapped to linkage group 8 and was loosely linked to Tr33 at a distance of 13.5 cM. Four QTLs for 100 seed weight (located on LG4 and LG9), seed number plant^-1 (LG4), days to 50% flower (LG3) were identified. This intraspecific map of cultivated chickpea is the first that includes genes for important morphological traits. Synteny relationships among STMS markers appeared to be conserved on six linkage groups when our map was compared to the interspecific map presented by Winter et al. (2000). This revised version was published online in August 2006 with corrections to the Cover Date.     

Estimation of genetic components of variation for salt tolerance in chickpea using the generation mean analysis

Chickpea (Cicer arietinum L.) is known to be salt-sensitive and in many regions of the world its yields are restricted by salinity. Recent identification of large variation in chickpea yield under salinity, if genetically controlled, offers an opportunity to develop cultivars with improved salt tolerance. Two chickpea land races, ICC 6263 (salt sensitive) and ICC 1431 (salt tolerant), were inter-crossed to study gene action involved in different agronomic traits under saline and control conditions. The generation mean analysis in six populations, viz. P₁, P₂, F₁, F₂, BC₁P₁ and BC₁P₂, revealed significant gene interactions for days to flowering, days to maturity, and stem Na and K concentrations in control and saline treatments, as well as for 100-seed weight under salinity. Seed yield, pods per plant, seeds per plant, and stem Cl concentration were controlled by additive effects under saline conditions. Broad-sense heritability values (>0.5) for most traits were generally higher in saline than in control conditions, whereas the narrow-sense heritability values for yield traits, and stem Na and K concentrations, were lower in saline than control conditions. The influence of the sensitive parent was higher on the expression of different traits; the additive and dominant genes acted in opposite directions which led to lower heritability estimates in early generations. These results indicate that selection for yield under salinity would be more effective in later filial generations after gene fixation.     

Validation of the two-gene epistatic model for vernalization response in a winter × spring barley cross

A two gene epistatic model in which a dominant “winter growth habit” allele at Vrn-H2 encodes a repressor with a corresponding binding site in a recessive vrn-H1 allele explains the vernalization response phenotypes in an array of barley germplasm. In order to validate the model genetically, we developed an F ₂ population (and F ₂-derived F ₃ families) from the cross of Hardy (winter) × Jubilant (spring). Using gene-specific primers, we determined the Vrn-H1 and Vrn-H2 allele architecture of each F ₂ plant and we measured the growth habit phenotype of each F ₂ plant via phenotyping of its F ₃ progeny under controlled environment conditions. We used a set of treatments involving plus/minus vernalization under long photoperiod and vernalization under short photoperiod. Alleles at the two loci showed expected patterns of segregation and independent assortment. Under long day conditions, the two Vrn genes were the primary determinants of heading date, regardless of the vernalization treatment. Under short photoperiod, the effects of these loci were not significant. There was incomplete dominance at Vrn-H1: heterozygotes were significantly later to head than Vrn-H1Vrn-H1 genotypes. Vrn-H2 genotypes were also significantly later to head, even when plants were vernalized. These results validate the two-gene epistatic model for vernalization response under long-day conditions. The results under short photoperiod, and the variance in flowering with vernalization, confirm that while the two Vrn genes are the primary determinants of vernalization response, they are part of a larger interactome that determines the timing of the vegetative to reproductive transition.     

Inheritance of stem termination in pigeon pea (Cajanus cajan (L.) Mill sp.)

Summary Inheritance studies on the stem termination in pigeon pea using F₁, F₂ and F₃ generations of two crosses between determinate and indeterminate lines suggested that two dominant genes with epistatic (inhibitory) interaction of one of them control the interminate growth habit. The gene symbols D. idid and ddIdId have been designated to the parental plants with determinate and indeterminate growth habits, respectively. The gene IdId was epistatic (inhibitory) to the gene D giving a ratio of 13 indeterminate: 3 determinate inthe F₂'s observed. F₃ segregation supported the proposed model on the mode of inheritance.     

Antibiosis mechanism of resistance to pod borer, Helicoverpa armigera in wild relatives of chickpea

The pod borer, Helicoverpa armigera, is one of the major constraints to chickpea production worldwide. The levels of resistance to pod borer in the cultivated chickpea germplasm are moderate, and therefore, we studied the reaction of 32 accessions of wild relatives of chickpea for resistance to H. armigera under greenhouse conditions. Accessions ICC 17257, IG 70002, IG 70003, IG 70012, (Cicer bijugum), IG 69948 (C. pinnatifidum), IG 69979 (C. cuneatum), IG 70032, IG 70033, IG 70038, and IG 72931 (C. judaicum) showed lower leaf feeding, a drastic reduction in larval weight, and poor host suitability index at the vegetative and/or flowering stages of crop growth as compared to the cultivated chickpeas. Based on percentage pods damaged by 5th day (< 52% pods damaged compared to 90% pods damaged in Annigeri), and percentage weight gain by the larvae (< 35% weight gain compared to 366% weight gain on ICCV 2); accessions IG 69979 (C. cuneatum), IG 70003, IG 70022, IG 70016, IG 70013, IG 70012, IG 70010, IG 70001, IG 70018, and IG 70002 (C. bijugum), and IG 72953 (C. reticulatum) showed high levels of resistance to H. armigera. Larvae of H. armigera weighed < 50 mg when reared on C. pinnatifidum (IG6 9948 and IG 70039), and C. judaicum (IG 72931) compared to 301.95 mg on C. arietinum (ICCC 37 – the cultivated chickpea). Larval weights on many accessions of the wild relatives of chickpea were much lower than those on the cultivated chickpeas, indicating the existence of different mechanisms of resistance to H. armigera. There was no pupation and adult emergence when the larvae were reared on accessions of C. pinnatifidum (IG 69948 and IG 70039), and C. judaicum (IG 69980, IG 70032, IG 70033 and IG 72931). The wild relatives of chickpea showing high levels of antibiosis to H. armigera can be used to introgress diverse resistance genes into cultivated chickpea to increase the levels and diversify the basis of resistance to this insect. An erratum to this article is available at .     

Cytomorphological studies in an intergeneric hybrid between Gossypium hirsutum L. (2n=52) and Hibiscus panduraeformis Burm.

Summary An intergeneric hybrid (2n=38) between Gossypium hirsutum L. (2n=52) × Hibiscus panduraeformis Burm. (2n=24) was obtained by pollinating about 2000 flower buds of G. hirsutum var. Gregg Male Sterile with pollen from H. panduraeformis. The F₁ hybrid was intermediate in plant habit, but possessed gossypol glands and nectaries on the leaves, bolls containing seeds with fuzz and lint as dominant characters of G. hirsutum. Flowers with yellow corolla and anthers; purple petal spot, profuse growth of epidermal hairs on all plant parts including the boll sutures, and jassid tolerance were dominant characters of H. panduraeformis. The partial fertility of the F₁ indicated the possibilities of combining jassid and drought tolerance of H. panduraeformis with the desired economic characters of G. hirsutum for rainfed cultivation.The F₁ hybrid showed various meiotic irreguarities and about 40% pollen sterility. Formation of the normal bivalents occurred quite frequently suggesting a close relationship between the parental species. The sterility observed in the hybrid may be due to small structural differences between the chromosomes of the two genera and meiotic abnormalities.