ince, Bangladesh is a developing nation (Nabi, Ahmed, & Rahman, 2017) and the banking institutions performs the most critical role in fostering the economic advancements of the country (S. A. N. B. Ahmed, 2017). Besides, in the competitive business realm, the service sector is capturing the leading position (Begum, Zehou, & Sarker, 2014). Consequently, the banking sector is anticipated to remain vigorous with a challenging and competitive atmosphere too. Therefore, the private commercial banking sector has been experiencing an age of tremendous challenges in improving productivity in the recent years. However, in the contemporary competitive world, business firms are uncompromisingly organizational aspect to enhance productivity (Bizri, 2018; Rahman & Chowdhuri, 2018; Yang, Simon, Wang, & Zheng, 2016). OCB means employee behaviors that are beneficial to the organization but not directly required by the formal reward system (Chahal & Mehta, 2010). Therefore, banks are gradually concentrating on OCB to delight clients and to enhance the quality of service (Begum et al., 2014).

Recent researches suggest that employee perceived HRM practices positively associated to the exhibition of OCB (Alfes, Shantz, Truss, & Soane, 2013; Cesário & Magalhães, 2017; Lam, Chen, & Takeuchi, 2009; Lin, Chen, & Chen, 2016). However, effective functioning of every HRM practice can enhance employees OCB in the organization (Begum et al., 2014). Precisely, TD increases pay, enrich skills essential at the office, develops performance and provides pleasure in the job, thus leads to superior levels of discretionary effort at the workplace (Felstead, Gallie, Green, & Zhou, 2010).

Also, TD had a significant influence on OCB (K. Ahmad, 2011; N. O. A. Ahmed, 2016). Besides, TD influences the attitudes and behavior of employees (N. O. A. Ahmed, 2016; Krishnan, Liew, & Koon, 2017; Tang & Tang, 2012). Since previous researches provide evidence that TD has an influence on OCB in various service sectors including commercial banks, therefore the current study focuses on empirically investigating the relationship of TD on OCB in private commercial banks in Bangladesh.

To enhance employee productivity in organizational setting, organizational citizenship behavior (OCB) is considered to be a vital factor in increasing efficiency (Bizri, 2018 Organ -the father of OCB defines OCB as "individual behavior that is discretionary, not directly or explicitly recognized by the formal reward system, and that in the aggregate promotes the effective functioning of the organization" (1988, p.4). Besides, Chattopadhyay (2017) noted that whenever the employees perform beyond their stipulated job description, these efforts lead to excellence in organizational performance. Moreover, attitudinal variables influence OCB rather employees' knowledge, skills and abilities (KSAs) (Jain & Rizvi, 2018). Further, OCBs cannot be made compulsory since they are the expressions of personal motivation within a group or organizational perspective (Pickford & Joy, 2016)

Human resource management practices denote a set of undertakings that targets to attract, to train and develop, to motivate and to retain employees (

Social exchange theory (SET) conceptualized in the study of (Blau, 1964) and (Homans, 1958(Homans, , 1961) ) seems to be the most substantial theoretical viewpoints in management, sociology and social psychology (Cropanzano et al., 2017). Alfes, Shantz, Truss, & Soane (2013) assumed SET to be the theoretical framework in assessing the link between human resource management practices and OCBs. Besides, Elstad, Christophersen, & Turmo (2011) stated that the SET is a theoretical explanation to explain OCB. Moreover, SET is one the most influential theoretical paradigms to recognize organizational behavior (Cropanzano & Mitchell, 2005).

SET signifies that HRM practices should convey a positive signal to the employees about organizations' concern for the employees' welfare and management desires to maintain an enduring relationship with them (Gould-Williams, 2016). Besides, the SET is also labeled in examining employee's perception of HRM practices and their effect on employee attitude at the workplace (Ko & Hur, 2014). Therefore, suitable HRM practices are marked as the commitment from the management toward the employees and expect that the employees will reciprocate with superior commitment and work engagement (Garg & Sharma, 2015). Consequently, workers demonstrate constructive attitudes and behaviors (Kim & Ko, 2014) To expect presence of citizenship behavior naturally in employees is nearly challenging (N. O. A. Ahmed, 2016;Werner, 1994). For that reason, organizations can motivate them to demonstrate more OCB providing TD (K. Ahmad, 2011). Besides, training and development play a crucial role to influence employees to elicit citizenship behavior (N. O. A. Ahmed, 2016;Werner, 1994).

Recently, a study on 134 Pakistani university teachers showed that training and development opportunities have a significant positive relationship with organizational commitment consequently, enhance organizational citizenship behavior (A. Noor, 2009). Besides, Ahmed (2016) conducting an investigation in the banking sector of Sudan to evaluate the influence of HRM practices on OCB, found that HRM practice TD has a moderate but significant positive effect on OCB. Similarly, TD programs positively influence the employee's service-oriented OCB as empirical from telecommunication and internet service providers in Malaysia (Krishnan et

To conduct the current research the targeted population includes all the employees of private commercial banks in Bangladesh irrespective of their managerial levels. However, no recent evidence found regarding the exact size of human resource poll working in these banks. A newspaper report published three years ago mentioned the numbers of employees in the banking sector to be of 50132, and among them, 7491 are female which is 13% of total employees in the banking sector (Asaduzzaman, 2016). However, to achieve the objective of the current study, the researches collected relevant data from the employees of 67 conveniently selected branches of 31 commercial banks located in Dhaka city only. The researchers distributed 250 questionnaires based on convenient sampling and received 173 filled out questionnaires with a response rate of 69.20%. However, avoiding unusable questionnaires the current research concluded its findings on 141 appropriately filled out questionnaires. Consequently the sample size of the current study is N=141.

To measure the training and development activities of HRM practices, the research used four items, which were adapted from (Woods & Mayer, 2005) scale of HR practices and using these items require the response on five-points Likert scale ranging from 1 = strongly disagree to 5 = strongly agree. To ensure the simplicity of the items and to reduce the ambiguity to the respondents some modifications was made by the researcher.

Sample items include, "My bank provides formal training programs to teach new hires the skills they need to perform their jobs" and "In my bank, training programs are evaluated in order to improve their effects."

To evaluate OCB, the researchers adapted the OCB Scale developed by Lee & Allen (2002). This scale contains sixteen items for two dimensions of OCB (e.g., OCBI and OCBO) where each dimension has eight items. Sample items of the scale are "Help others who have been absent,' "Assist others with their duties," "Defend the organization when other employees criticize it" and "Offer ideas to improve the functioning of the organization."

Many famous studies like ( Rahman & Chowdhuri, 2018) used this scale. Fivepoints Likert scale has been used ranging from 1 = strongly disagree to 5 = strongly agree. The researchers did several negligible wording changes to items to avoid difficulties and to ensure clarity to the respondents.

The researchers used statistical data analysis software 'Statistical Package for the Social Sciences (SPSS)' version 23.0 to prepare and analyze data. Pearson correlation was employed to investigate the degree and nature of relationships among TD and OCB dimensions. As a final point, to find out the effect of TD on OCBI and OCBO two simple linear regression models were developed.

The current study draws its findings on data from 141 employees from private commercial banks operating in Bangladesh. Among 141 respondents 78% were male and the remaining 22 % were female. About 68.10% of respondents were from 30-39 years of age, besides, married respondents were 66.00%. Moreover, 75.20% of respondents worked for their current organizations for the more than1 year but less than10 years. However, 79.40% of respondents had completed their post-graduation/ master's degree.

The independent variable training and development (TD) had a mean score of 3.81 and the SD = 0.51 specified that there is a presence of fair TD practice in private commercial banks operating in Bangladesh. Besides, OCBI directed towards specific individuals (OCBI) produced a mean of 4.06 and SD = 0.45. Therefore, implies that employees in private commercial banks exhibit a high level of OCBI. Moreover, dependent variable OCB directed towards organization (OCBO) had a mean score of 3.76 which is lower than OCBI, and a relatively higher SD = 0.56 than OCBI. Therefore, demonstrated that the exhibition of OCBO in employees fluctuates a lot than OCBI.

The study found that training and development (TD) and OCBI-OCB directed at specific individuals were also positively interrelated. However, the degree of the relationship between TD and OCBI was moderate (r =.416) and was significant at the p< 0.01 significant level. In contrast, TD, and OCBI-OCB directed at specific individuals had a positive correlation between them moreover, the strength of the relationship between TD and OCBO was strong (r=.701) as well as was significant at p< 0.01 significant level. Thus, when there is a well-established as well as outcome-oriented and well-accepted training and development opportunities that would result in the demonstration of OCB at the workplace. Here, the adjusted R² = 0.167 with the R² = 0.173, demonstrating that the predictor variable TD-training and development (X) can explain nearly 17% of the total variability of the dependent variable OCBI-OCB directed towards specific individuals (Y). So, there must have more influential variables which effect OCBI. Besides, F (1, 139) = 29.15 > critical value of F (1, 139) = 3.909 moreover, corresponding significance level p<.05 signifying that independent variable TD (X) predicts the dependent variable OCBI (Y). ii. Training and Development (TD) and OCBO Here, R 2 = .491 and adjusted R² = .488. In this case, the R 2 = .491 indicates that about 49.10% of the variability of OCBO is accounted for the model as well as there must be one or more variables that explain the remaining portion of the variability in OCBO. The model is significant as F (1, 139) =134.192, which is far greater than the critical value F (1, 139) =3.909 and p<.05.

Further, calculated t value is 11.584 for training and development (Y), which is superior to the tabulated t (=1.656), and p<.05. Thus, it rejects null hypothesis, and accepts the alternative hypothesis (H 2 ), therefore, the value of the coefficient for training and development (b=.764) is significantly different from zero (0). However, the positive value of b indicates a significant positive linear relationship between TD (X) and OCBO (Y). Besides, hypothesis testing authorizes that a significant Further, for TD (X) calculated value of t (=5.399) > tabular value of t (=1.656), corresponding value of (p= 0.00) < significant level (p=0.05). Thus, it rejects null hypothesis and accepts the alternative hypothesis (H 1 ), besides, a positive value of the coefficient for TD (b = .368), indicates that there exists a significant positive linear relationship between TD and OCBI. The Y-intercept (a=2.658) indicated the expected OCBI (Y) when there is no TD (X). Alternatively, this is the OCBI (Y) when TD (X) is equal to zero, and other variables remain constant. Whereas, (b= .368) represents that a single unit increase in TD (X) would result in an increase of .368 times in OCBO. Thus, the Linear Regression Model would be as follows:

positive relationship between training & development and OCBO.

Therefore, the research can conclude that there is a significant effect of training and development practices of HRM on OCB and the nature of the relationship between them is positive. The finding of this exploration is similar to previous studies by Ahmed (2016) The findings provide an understanding of the relationship between OCB and TD practice of HRM practices and demonstrate that when organizations establish better TD practices for employees, they tend to display more OCBs (OCBO and OCBI). Accordingly, employees are expected to respond with positive attitudes and behaviors toward organization when organizations ensures effective TD practice of HRM practices. Therefore, the outcomes of the study support the Social Exchange Theory (SET), reflected to be the study of (George Caspar Homans, 1961) and (Blau, 1964).

The current research considerably endorses that there is a strong influence of employee training and development (TD) practice on organizational citizenship behavior (OCB) in private commercial banking industries in Bangladesh. Besides, previous literature support that OCB is acknowledged as pushing more effect on employee performance which organizations should employ to enhance organizational competencies, performance and finally organizational efficiency. To summarize, there is a considerable and beneficial magnitude of OCBs on organizations, therefore, executive managers and HR managers should pay considerable responsiveness in designing and implementing training and development (TD) activities to results in OCBs (both OCBI & OCBI), and consequently confirming enhanced organizational performance.

This assessment on effects of training and development (TD) practices on organizational citizenship behavior (OCB) has confirmed that there is a remarkable effect of TD on OCB. However, this research contains several limitations that must be acknowledged. First of all, the study focused on a single developing country, Bangladesh besides, samples were conveniently selected from a single location-Dhaka city. Consequently, the outcomes cannot be universally applicable. Secondly, the research draws its findings relatively on a smaller sample size. Therefore, the results of the study may not represent the whole sample population. Finally, the study was conducted only on the general employees working in branch-level banking and performing day to day activities. Other technical and particularly skilled employees such as mechanical staffs, clerical staffs and IT experts were not involved. Hence, the results of the research cannot be generalized in the broader perspective.

Though the research has some limitations that threaten the implication of this research, the study can headed to a number of directions. First of all interested researchers could conduct longitudinal studies to investigate the changes over time. Secondly, similar study can conducted to find out the influences of other HRM practices (e.g. HR planning, recruitment and selection, communication, performance appraisal, compensation management, compliance, employee retention, employee relations and career management) on OCB both in banking sector and other industrial areas at home and abroad as well. Thirdly, future researchers can examine the relationship among the demographic variables (age, sex, level of education, and years of service) and OCB. Finally, further investigation can be conducted to find the relationship among OCB and its potential antecedents (e.g., employee characteristics, justice perception, and psychological contract and leadership styles).

The present research contributes to the comprehensive understanding of training and development (TD) practices and organizational citizenship behavior (OCB) in private commercial banks operating in Bangladesh. The research identified that there is a powerful positive link between training and development practice and citizenship behavior.