Journal of Plant Genetics and Breeding
Open Access

Sweet pepper; Stability; Yield; Maturity

Sweet pepper is a versatile crop; it is mainly used in preparation of various products such as soups, stews, sausage, cheese, snacks, salad dressing, sauces, pizza, confectionaries, beverages etc. and to a limited extent canned, pickled or consumed as a fermented product which make it a major commodity in culinary industry. The consumption of sweet pepper is on the increase all over the world. It has become a multibillion dollar industry, as well as a part time hobby for home gardeners. Moreover the coloured bells command a higher market price and provide an alternate channel for this crop.

The genotype × environmental (G × E) interactions are major concern to plant breeders for developing improved cultivars. For a cultivar to be commercially successful, it must perform well across a range of environments in which the cultivar has to be grown. Among the different models proposed for estimating stability of genotypes by various workers Eberhart and Russel has been most extensively used to identify stable genotypes for important quantitative traits over environments in various crop species. Eberhart and Russel defined a stable genotype as one having high mean with a regression close to zero [1]. Accordingly, genotypes could be classified as, below average stable performing well only in favourable environments (b_i > 1). Above average stable adapted specifically to poor environments (b_i< 1) and average stable performing well in most of the environments (b_i = 1).

The present investigation was carried out to determine adaptive potential and phenotypic stability of fifteen coloured capsicum genotypes grown at three locations during Kharif 2018. The experiment was laid out in a completely randomized block design with three replications at each location. The observations recorded on various maturity and yield attributing traits were subjected to statistical and biometrical analysis and the results thus obtained are described as under.

Pooled analysis of variance over three environments revealed highly significant differences among genotypes for all the characters (Table 1). Mean sum of squares due to environments were significant for all the characters. Mean sum of squares due to genotype × environments were also significant for all characters.

Table 1: Mean squares of pooled environments for maturity and yield attributing traits in Coloured Capsicum (Capsicumannuum L. var. grossum Sendt.).

The effect of environment in a stability analysis study is quantified through environmental index. The environmental indices for different traits are presented in Table 2. The present investigation revealed that the environment E1 i.e. (Experimental Farm of Division of Vegetable Science, SKUAST-Kashmir, Shalimar) was the most favourable environment for the expression of all traits as indicated by the highest environmental index for number of fruits plant-1 (0.731), average fruit weight (3.325), fruit yield plant-1 (0.090) and fruit yield plot-1 (0.913) and lowest environmental index for days to first flowering (-0.895) and days to first harvest (-0.908). E1 was also found to be favourable for expression of days to first fruit set (-0.339). The environment E2 i.e., Vegetable Farm of Krishi Vigyan Kendra, Haran, Budgam was most favourable for expression of traits viz., days to first fruit set (-0.859). E2 was also favourable for expression of various other traits like days to first flowering (-0.544), days to first harvest (-0.362), number of fruits plant-1 (0.018), average fruit weight (0.030), average fruit yield plant-1 (0.009) and average fruit yield plot-1 (0.002). The environment E3 i.e., Regional Research Station and Faculty of Agriculture, Wadura was found to be unfavourable for expression of all traits. The influence of various environments as depicted by estimates of environmental indices was also reported by Tembhurne and Rao [2].

Table 2: Environmental indices for various maturity and yield attributing traits in Coloured Capsicum (Capsicum annuum L. var. grossum Sendt.).

Mean squares of stability analysis in respect of various maturity and yield attributing traits under study are summarized in the Tables 3a and 3b. The pooled analysis of variance for stability of fifteen genotypes over three environments revealed significant variation among genotypes for all traits indicating the presence of large amount of variability in the material chosen for study. The mean sum of squares due to environments were significant for all traits indicating that environments selected to conduct the study were variable and influenced the expression of traits. Similar results have been reported by Tembhurne and Rao, Ummayiah et al., Spaldon et al. etc [2-4].

Table 3a: Mean squares of stability analysis for maturity and yield attributing traits in Coloured Capsicum (Capsicun annuum L. var. grossum Sendt.).

Table 3b: Mean squares of stability analysis for maturity and yield attributing traits in Coloured Capsicum (Capsicum annuum L. var. grossum Sendt.).

Environments (linear) component of variance was significant for all traits indicating that environmental effects were predictable. These results agree with the findings of Jyothi et al., Tembhurne and Rao, Ummiayah et al and Spaldon et al. [2-5]. The linear component of genotype × environment was also significant for all traits indicating the significant linear response of genotype to environmental changes for these traits. Non-significant effect of genotype × environment (linear) for rest of the traits indicated that the different genotypes did not differ genetically in their response to different environments. The linear component was found to be greater in magnitude than the corresponding non-linear component for almost all the traits suggesting that the performance of genotypes across environments could be predicted with greater precision for these traits. The pooled deviation was significant for days to first fruit harvest and average fruit weight indicating the important contribution of non-predictable component in respect of these traits. Similar results have been reported by Srividhya and Ponnuswami, Tembhurne and Rao, Ummyiah et al., Spaldon et al. [2-4,6].

The genotypes exhibiting stability for different traits are given in Table 4a and 4b. In the present study, the estimates of regression coefficients for fifteen genotypes ranged from 0.46 to 2.16 for days to first flowering, 0.56 to 1.43 for days to first fruit set, 0.18 to 1.76 for days to first harvest, -0.26 to 3.05 for number of fruits plant-1, 0.24 to 1.91 for average fruit weight, 0.24 to 2.15 for average fruit yield plant-1 and 0.23 to 2.13 for fruit yield plot-1indicating that the genotypes possess different set of alleles for adaptation across environments.

Table 4a: Stability parameters for various maturity and yield attributing traits in Coloured Capsicum (Capsicum annuum L.var. grossum Sendt.).

Table 4b: Stability parameters for various maturity and yield attributing traits in Coloured Capsicum (Capsicum annuum L.var. grossum Sendt.).

Since early flowering is a desirable character in sweet pepper, the genotypes requiring less number of days to flowering as compared to the population mean would be desirable. Early flowering together with non-significant regression coefficient and non-significant deviation from regression indicating average stability were identified as SH-SP-2, SH-SP-4, SH-SP-5, SH-SP-14, SH-SP-15, SH-SP-16 and Nishat-1. The genotypes requiring less number of days for first flowering as compared with general mean together with significant but less than one regression coefficient together with non-significant deviation from regression would indicate above average stability. None of the genotypes exhibited above average stability. SH-SP-11 with regression coefficient value significantly greater than unity along with non-significant deviation from regression showed below average stability and was significantly adapted to favorable environments. The mean performance of both genotypes being greater than population mean was undesirable. Early fruit set is again a desirable trait. The genotypes exhibiting average stability were identified as SH-SP-4, SH-SP-14, SH-SP-15, SH-SP-16 and Nishat-1. Above average stability was exhibited by the genotypes SH-SP-2 though taking more number of days to first fruit set. Similarly, early fruit harvest is a desirable character. The genotypes showing average stability were identified as SH-SP-3, SH-SP-4, SH-SP-5, SHSP- 14, SH-SP-15 and Nishat-1. The genotypes SH-SP-9 and SH-SP-10 depicted unpredictable behavior with respect to days to first harvest. None of the genotypes exhibited above average stability.

The genotypes SH-SP-4, SH-SP-7, SH-SP-8, SH-SP-10, SH-SP-14, SH-SP-16 and Nishat-1 showed average stability for number of fruits plant-1. The genotype SH-SP-1 showed above average stability. For average fruit weight only two genotypes SH-SP-2 and SP-12 exhibited average stability. The genotypes SH-SP-5, SH-SP-7, SH-SP-8, SHSP- 9 and SH-SP-15 showed unpredictable behavior as indicated by significant values of S2 di and prediction of stability was not reliable. For average fruit yield plant-1, SH-SP-1, SH-SP-7, SH-SP-14 and SH-SP-16 showed average stability. Nishat-1 showed above average stability. SH-SP-8 showed significant deviation from regression indicating that prediction on stability of this genotype is not reliable. For average fruit yield plot-1, SH-SP-1, SH-SP-7, SH-SP-8, SH-SP-14 and SH-SP-16 average stability. Nishat-1 showed above average stability. The stability of SH-SP-9 was not predictable.

As indicated by the stability parameters, the genotypes that were well adapted to all the environments Table 5 were SH-SP-2, SH-SP-4, SH-SP-5, SH-SP-14, SH-SP-15, SH-SP-16 and Nishat-1 for early flowering; SH-SP-4, SH-SP-14, SH-SP-15, SH-SP-16 and Nishat-1 for early fruit set; SH-SP-3, SH-SP-4, SH-SP-5, SH-SP-14, SH-SP-15 and Nishat-1 for early fruit harvest; SH-SP-4, SH-SP-7, SH-SP-8, SHSP- 10, SH-SP-14, SH-SP-16 and Nishat-1 for number of fruits plant-1; SH-SP-2 and SH-SP-12 for average fruit weight; SH-SP-1, SH-SP-7, SH-SP-14 and SH-SP-16 for average fruit yield plant-1 and SH-SP-1, SH-P-7, SH-SP-8, SH-SP-14 and SH-SP-16 for fruit yield plot-1. Similar results with respect to various traits have been reported by Srividhya and Ponnuswami, Ummyiah et al., Spaldon et al. [3,4,6].

Table 5: Stable genotypes of Coloured Capsicum (Capsicum annuum var. grossum Sendt.) with respect to different traits.

Table 6: Stability of Coloured Capsicum (Capsicum annuum var. grossum Sendt.) with respect to different traits.

The genotypes which show unpredictable behavior as depicted by significant deviation from regression irrespective of regression coefficient whether it is significant or not were SH-SP-9 and SH-SP-10 for days to first fruit harvest; SH-SP-5, SH-SP-7, SH-SP-8, SH-SP-9 and SH-SP-15 for average fruit weight; SH-SP-8 for fruit yield plant-1 and fruit yield plot-1 .

Table 6 depicts the total number of traits for which each genotype is stable. SH-SP-1 was found to be stable for average fruit yield plant-1 and average fruit yield plot-1; SH-SP-2 was found to be stable for days to first flowering and average fruit weight; SH-SP-3 was found to be stable for days to first fruit harvest; SH-SP-4 was found to be stable for days to first flowering, days to first fruit set, days to first fruit harvest and number of fruits per plant; SH-SP-5 was found to be stable for days to first flowering and days to first fruit harvest; SH-SP-7 was found to be stable for number of fruits plant-1, average fruit yield plant-1 and average fruit yield per plot; SH-SP-8 was found to be stable for number of fruits plant-1; SH-SP-9 was not found to be stable for any trait under study; SH-SP-10 was found to be stable for number of fruits plant-1; SH-SP-11 was not found to be stable for any trait under study; SHSP- 12 was found to be stable for average fruit weight; SH-SP-14 was found to be stable for days to first flowering, days to first fruit set, days to first fruit harvest, number of fruits plant^-1, average fruit yield plant^-1 and average fruit yield plot-1; SH-SP-15 was found to be stable for days to first flowering, days to first fruit set, days to first fruit harvest; SHSP- 16 was found to be stable for days to first flowering, days to first fruit set, days to first fruit harvest, number of fruits plant^-1, average fruit yield plant-1 and average fruit yield plot^-1 and Check (Nishat^-1) was found to be stable for days to first flowering, days to first fruit set, days to first fruit harvest and number of fruits plant^-1.

1. Eberhart SA, Russell WA (1966) Stability parameters for comparing varieties. Crop Sciences 6:36-40.

Indexed at     Google Scholar      Crossref

2. Tembhurne BV, Rao SK (2013) Stability analysis in chilli (Capsicum annum L.). J Spices Aromatic Crops 22:154-164.

Indexed at     Google Scholar

3. Ummyiah HM, Nayeema J, Baseerat A, Faheema M (2015) Stability analysis and genotype × environment interaction of some tomato hybrids under Kashmir conditions. VEGETOS 28:36-40.

Google ScholarCrossref

4. Spaldon S, Samnotra RK, Rinchan D, Choudhary D (2017) Stability analysis and genotype × environment interaction of quality traits in tomato (Solanum lycopersicum L.). Int J Curr Microbiol App Sci 6:1506-1515.

Google Scholar    Crossref

5. Jyothi HK, Patil MG, Santhosha HM (2012) Studies on stability of processing type genotypes of tomato (Solanum lycopersicum Mill.). J Horticulture Sci 7:138-141.

Indexed at    Google Scholar

6. Srividhya S, Ponnuswami V (2010) G × E interaction and stability of yield in paprika genotypes (Capsicum annuum var. longum) in Tamil Nadu. Electro J Plant Breed 1:297-300.

Indexed at      Google Scholar