Chilli Lines Research Articles

Exploration of Resistance in Chilli Varieties/Advanced Lines against Fusarium Wilt caused by Fusarium oxysporum f. sp. capsici

Chilli (capsicum annum L.) is an important edible spice crop grown in tropical areas of world due to its richness of nutrients like carotinoides, fibers, mineral components, oils, proteins and vitamins. A number of biotic and abiotic factors are challenging devastatingly the successful production of chilli. Among all of these factors, Fusarium wilt caused by Fusarium oxysporum f.sp.capsici (Foc) is a potential risk of declining its yield every year. Among all management approaches, use of resistant varieties is the best option towards Foc. For this purpose in contemporary study twenty five varieties/advanced lines of chilli were evaluated against Fusarium wilt under natural field conditions in research area, Department of Plant Pathology, University of Agriculture Faisalabad for two years 2017-18 and 2018-19 under randomized complete block design (RCBD). Results exhibited that none of varieties/advanced line expressedimmune response against the disease. Only one variety (BPVLC 14-1) was resistant with 18.76% disease incidence. Uttal, fengaio, Glaxy-2, Big daddy, GHHP 01, PH-275, Super sky AB, HPO33 and Super king were found moderately resistant (MR) with 21-40% disease incidence. Four varieties/advanced lines Hot-701. Hot shot, Omega and Silkey Red showed moderately susceptible response (MS) with 41-50% and Four (Super hot, Patyala F1, Angel F1 and Green king) were susceptible (S) with 51-70% incidence of Fusarium wilt. Seven (Tejal, BSS-410, Big Red AB, SB 6864-HM, Glory F1, Revival and Amber F1) varieties / advanced lines exhibited highly susceptible (HS) response.

Stability Analysis of Advanced Chilli Lines

Stability Analysis of Advanced Chilli Lines

Isolation and Identification of Molecular Markers for Fingerprinting of Chilli Hybrids & its Parental Lines

Chilli (Capsicum annum) is the predominant sp., which is cultivated in both hot and sweet papers. The maintenance of the genetic purity of chilli plant is a matter of great concern for the breeders. For genetic purity analysis, between true hybrids and off-types, breeders find out morphological differences between them, but this technique is cannot be recognized easily and also costly, tedious to score, and environmentally sensitive. Alternatively, molecular markers based genetic purity analysis can be employed. The molecular marker-based technique was thus used to overcome the conventional method drawbacks. The main objective of the study is to identify informative molecular markers (ISSR and RAPD) capable of distinguishing Chilli hybrids and their parental lines and their utilization in seed purity assessment. Five parental lines of Chilli (i.eCH10, CH12, CH530, CH709, CH734) were used for the production of 3 hybrids. Total 30 ISSR and 8 RAPD primers were selected for the study of 5 parental lines, among them 2ISSR and 1 RAPD primers produced unique fingerprinting across the hybrids. The ISSR marker UBC815 amplified alleles specific to different parental lines(CH10 & CH12) for hybrids (ACH112), The ISSR marker UBC 827, amplified alleles specific to different parental lines(CH709 & CH12) for hybrids (ACH179). Likewise, RAPD primer B20 for hybrid ACH 753 and their parental lines(CH734 & CH530). Thus, the above study showed that the aid of molecular markers is more reliable, highly efficient, and reproducible for assessing fingerprinting of Chilli commercial hybrid seeds with more accuracy.

Cytoplasmic male sterile lines with desirable combining ability enhance the concentration of biochemical attributes and total yield in Capsicum annuum under temperature stress conditions

The last couple of decades report showed that the chemical compounds (ascorbic acid, oleoresin, and capsaicin content) of chilli have a significant effect on human health, and increasing application of these important compounds especially oleoresin and capsaicin in various agro-food and pharmaceutical industries has resulted in their demand manifold. Hence, to fulfill the demands of industries, there is urgent need to identify wider adapted inbreds/ parental lines with significant combining ability effects to develop high yielding good quality hybrids with low seed cost. To address this, three newly developed cytoplasmic male sterile lines and 20 potential restorer lines were evaluated in a line × tester mating design to estimate combing ability for 15 plant growth, yield, and biochemical traits over three environments. Early season (low temperature condition, E1), main season (normal temperature condition, E2), and late season (high temperature condition, E3) constituted the three environments. The estimates due to general combining ability of lines, general combining ability of testers, and specific combining ability of crosses over environments were significant for all the traits evaluated, except due to general combining ability of lines for number of primary branches plant−1. In general, the magnitude of the additive variance (σ2A) was more than the non-additive variance (σ2D) except for number of primary branches plant−1 in E2, E3, and across the environments; and for plant height, plant spread, and number of fruits plant−1 in E3. The line CMS463D13A and the testers SL 475, IS 268, PP 402, FL 201, and C 142 were identified as potential parents to breed for high yielding good quality (ascorbic acid, oleoresin, capsaicin, and scoville heat units) genotypes suitable for early, main, and late season planting. Based on the specific combining ability estimates, promising crosses suitable for the respective crop seasons for fresh consumption and industrial purposes were identified. Across the environments, the cross CMS463D13A × IS 268 was promising for total yield plant−1, number of seed fruit−1, and capsaicin content. The cross involved good × good general combining ability parents and is a potential source to develop high yielding-pungent true breeding chilli lines.

Candidate Markers Assay for Capsicum Pungency

Effectiveness of candidate markers for differentiating the pungent, slightly pungent and non-pungent chilli lines and their use in marker assisted selection programmes was assessed. Two pungent C. annuum, one pungent C. chinense, two pungent C. frutescens, one non-pungent C. annuum, two non-pungent C. annuum var. grossum and two slightly pungent C. annuum var. acuminatum cultivars were analysed using MAP1 marker for locus Pun1, CS and B markers for locus CS, Pun11 marker for locus Pun1 of C. annuum and Pun13 marker for locus Pun1 of C. frutescens. This paper discusses the universal suitability of these candidate markers in MAS programmes for levels of pungency in Capsicum. Through sequencing of markers it is further shown that the proposed CS gene lies within the Pun1 locus and since Pun1 markers are missing in non-pungent and slightly pungent lines, we propose that genes other than Pun1 are involved in pungency mechanism in Capsicum spp.

Candidate markers assay for Capsicum pungency

Effectiveness of candidate markers for differentiating the pungent, slightly pungent and non-pungent chilli lines and their use in marker assisted selection programmes was assessed. Two pungent C. annuum, one pungent C. chinense, two pungent C. frutescens, one non-pungent C. annuum, two non-pungent C. annuum var. grossum and two slightly pungent C. annuum var. acuminatum cultivars were analysed using MAP1 marker for locus Pun1, CS and B markers for locus CS, Pun11 marker for locus Pun1 of C. annuum and Pun13 marker for locus Pun1 of C. frutescens. This paper discusses the universal suitability of these candidate markers in MAS programmes for levels of pungency in Capsicum. Through sequencing of markers it is further shown that the proposed CS gene lies within the Pun1 locus and since Pun1 markers are missing in non-pungent and slightly pungent lines, we propose that genes other than Pun1 are involved in pungency mechanism in Capsicum spp.

Performance of chilli (Capsicum annuum L.) lines with different plantation time during rainy season

The experiment was conducted during April to September, 2016 at Spices Research Sub-Centre, Faridpur to evaluate the performances of four chilli lines with BARI Morich-2 as check and to select the suitable planting time during rainy season. The experimental field belongs to high land of Low Ganges River Floodplain (AEZ 12) with clay loam in texture. The experiment was laid out in RCB design with three replications. Four lines and a variety viz., C0711, C0712, C0713 and C0714 and BARI Morich-2 as check were evaluated with three planting time viz., 01April, 15 April and 30 April. Seedlings of 40 days old were transplanted maintaining of 50cm × 50cm spacing in each case. The crop (Green chilli) was started to harvest from July and completed on August-September, 2016.Among the lines, C0712 emerged as superior in terms of maximum number of fruits/plant (225.7) and weight of fruits/plant (478.6g) and fresh yield (15.43t/ha) while the highest single fruit weight (3.217 g) was found from C0714. The 15 April planting date emerged as best in terms of maximum weighed fruit (2.661g), weight of fruits/ plant (409.3 g), number of fruits/plant (182.5) and fresh yield (12.14 t/ha). The interaction effect showed that lineC0712 transplanted on 15 April gave the heavier fruits/plants (542.2 g) with maximum number of fruits/plant (241.3)and maximum fresh yield (16.73 t/ha). The 15 April planting was ideal for rainy season chilli evaluation and the line C0712 was the most stable performing line with respect to different planting dates.

EFFECT OF ENVIRONMENTAL FACTORS ON CHILLI LEAF CURL DISEASE DEVELOPMENT IN CHILLI AND ITS MANAGEMENT

Leaf curl disease in chilli is an important yield constraint in chilli production in Pakistan and India. In this study, four chilli lines / varieties were grown under field conditions and development of disease on each variety was studied in relation to environmental factors. Effect of environmental factors including maximum and minimum temperature, rainfall and relative humidity on whitefly population and chilli leaf curl disease development was investigated throughout the crop growth period. Increase in maximum and minimum temperature resulted in increase in whitefly population. However, temperature was negatively correlated with disease development. Rainfall had a negative effect on whitefly population whereas it was positively correlated with disease development. Relative humidity was positively correlated with disease development whereas whitefly population was reduced due to increase in relative humidity. Extracts of neem, eucalyptus and akk were used for the management of disease at 1%, 2% and 5% concentrations which were found effective in disease management.

SUSCEPTIBILITY OF CHILLI LINES / VARIETIES TOWARDS CHILLI LEAF CURL VIRUS AND ITS MANAGEMENT THROUGH VECTOR CONTROL

Chilli leaf curl virus (ChiLCV) is a serious problem for chilli production in Pakistan and India. In this study, fourteen different chilli lines / varieties were screened for their resistance/susceptibility towards ChiLCV in open field trials. Data of disease severity and disease incidence was recorded on weekly basis. Out of all varieties screened, Tatapuri Chilli and CH111 showed high susceptibility towards the chilli leaf curl disease. Talhari, CH 99, CH103, CH 106, CH107, CH108, CH109, GSL111 showed susceptible response whereas CBS1292 showed moderately susceptible response towards the disease. Only two cultivars Hybrid-46 and Hot Queen were found as moderately resistant. The screening experiment showed that most of the chilli varieties are susceptible to chilli leaf curl disease and resistance is lacking in local germplasm. Furthermore, three insecticides: Imidacloprid, Polo and Emamectin were tested for their efficacy for the management of disease and whitefly vector in field conditions at weekly intervals. Out of three insecticides, Polo gave best results as compared to Emamectin and Imidacloprid against chilli leaf curl disease and whitefly vector.

Screening of chilli pepper (Capsicum spp.) lines for resistance to the begomoviruses causing chilli leaf curl disease in India

Resistance breeding program relies on identification of stable resistant sources. It starts with first identifying lines free from disease when screened under field followed by their screening by challenge inoculation for further confirmation of their resistance behavior. Following this approach, in the present study 60 germplasm lines of Capsicum annuum L., one each of C. baccatum, C. chinense, C. chacoense and two of C. frutescens and were assessed for resistance to leaf curl disease under field screening. As screening was carried out under natural disease conditions, chances of escape cannot be rule out. To ascertain the response of the identified chilli lines for resistance to leaf curl disease, the experiment was undertaken including the identified resistant lines for three more consecutive seasons with susceptible lines namely Pusa Jwala as infector rows at regular intervals to confirm their resistance response. At the end of first season of screening, sixteen lines were isolated (all of C. annuum species) showing mild or no disease symptoms in comparison to other lines under test. The screening process was continued for three seasons and the lines found resistant at the end of one season were screened in the next season also, while the susceptible lines were excluded from the study. At the end of four seasons of screening trial, three lines namely DLS-Sel-10, WBC-Sel-5 and PBC-142 showed resistance against leaf curl disease.

Combining ability estimates in virus resistant and susceptible lines of chilli (Capsicum annuum L.).

Combining ability estimates in virus resistant and susceptible lines of chilli (Capsicum annuum L.).

Final discussion

Resistance breeding program relies on identification of stable resistant sources. It starts with first identifying lines free from disease when screened under field followed by their screening by challenge inoculation for further confirmation of their resistance behavior. Following this approach, in the present study 60 germplasm lines of Capsicum annuum L., one each of C. baccatum, C. chinense, C. chacoense and two of C. frutescens and were assessed for resistance to leaf curl disease under field screening. As screening was carried out under natural disease conditions, chances of escape cannot be rule out. To ascertain the response of the identified chilli lines for resistance to leaf curl disease, the experiment was undertaken including the identified resistant lines for three more consecutive seasons with susceptible lines namely Pusa Jwala as infector rows at regular intervals to confirm their resistance response. At the end of first season of screening, sixteen lines were isolated (all of C. annuum species) showing mild or no disease symptoms in comparison to other lines under test. The screening process was continued for three seasons and the lines found resistant at the end of one season were screened in the next season also, while the susceptible lines were excluded from the study. At the end of four seasons of screening trial, three lines namely DLS-Sel-10, WBC-Sel-5 and PBC-142 showed resistance against leaf curl disease.

Breaking Resistance in Chilli To Root-Knot Nematode By Fungal Pathogens

Thirty one cultivars or lines of chilli were screened in the glasshouse against Meloidogyne incognita (Kofoid & White) Chitwood. Cultivars or lines which showed resistance were retested in a field infested with this nematode. The role of Rhizoctonia solani and Pythium aphanidermatum, fungi causing collar rot and damping off, was investigated in the breakdown of resistance in Jowala and Longthin Faizabadi, respectively resistant and moderately resistant to this nematode. Some of the cultivars or lines which showed some resistance in the glasshouse were found to lose it under field conditions. R. solani and P. aphanidermatum were implicated in the breakdown of resistance of Jowala and Longthin Faizabadi to this nematode.