Study on Correlations for Morpho-Physio Traits of Six Wheat Cultivars

Current research was conducted to analyze the coefficient and distribution of direct and indirect influence of yield components and earliness characteristics in wheat genotypes. Both experiments were carried out at the Pot House of the (NIA Nuclear Institute of Agriculture, Tandojam) (Latitude: 25.433. Longitude: 68.533), the experiment was established as a randomized complete block design (RCBD). There were six varieties of wheat, namely IBWSN1010, IBWSN 1025, TD1, ESW9525 Chakwal86 and Khirman, which were used to study the correlation coefficient between morphological and physiological traits. The study was based on fifteen (15) morphologically and physiologically traits that were observed. The analysis of variance showed significant differences between the characteristics of the varieties. The ESW9525 showed better performance for all morphological and physiological traits. The correlation and the coefficient analysis showed that the days to maturity and the days to growth predicted significant positive predictions related to the height of the plant (cm) and the length of the ear. Days to 75% heading and days to 75% maturity showed negative and positive effects for osmotic potential, relative water content in% and total chlorophyll content in%. Plant height (cm) had negative and positive and significant with tiller plant -1 . Therefore, in our research trial, variety ESW9525 may be favorable for hybridization in order to produce a promising and drought tolerant wheat cultivar.


Introduction
Correlation studies are very useful for breeders to improve drought tolerance in the sense that any physiological or yield trait with high heritability could be used as indirect selection criteria to improve yield in arid environments (Jatoi et al., 2011).The correlation and coefficient analysis quantifies the interrelationship of the different components of income and also shows whether the effect is directly reflected in income or other ways can be used to achieve an effect.Wheat yield fluctuates with the environment and genetic interactions.Selection to improve grain yield can only be more effective when genetic material showing variability (Khaliqe et al., 2004;Yasin & Singh, 2010).Wheat is the most cultivated and consumed food grain in the world (Farooq et al., 2011).With progressive climatic changes, global increasing scarcity of water resources and deteriorating ecological environment strongly influence on the production of wheat (Singh & Chaudhary, 2006).The continued increase in wheat production could be attributed to the development of various modern technologies in conjunction with potentially highyielding wheat varieties.The analysis of the variability of different traits and the presence of a specific trait with another trait that contributes to crop performance and would be the first priority for a successful breeding program (Mary & Gopalan, 2006).In the case of wheat genotypes, genetic variability can be estimated on the basis of quantitative characteristics.Scheduled parenting is very important for successful breeding.In crops, changes in anatomical and physio-biochemical characteristics due to resistance to drought could be used to develop new genotypes and achieve better production under conditions of water stress (Martínez et al., 2007).However, understanding and choosing the biochemical and physiological basis of tolerance to water stress in plants is important for breeding the crop (Abro et al., 2019). . appl. Res in Plant Sci. Vol. 3(1):198-205, 2022 Abro et al., www.joarps.org 199 An experiment was carried out in 2018-2019 growing season at the pot house of Nuclear Institute of Agriculture NIA Tandojam to observe the correlation coefficients of the morphological and physiological characteristics of 6 different varieties of wheat (Triticum aestivum L.), namely IBWSN1010, IBWSN 1025, TD1, ESW9525, Khirman and Chakwal86.The seeds were sown in controlled cemented tanks (size 3x3x1 cubic meters), filled with sandy loam soil, with three replications in the Random Complete Block Design (RCBD).The data of fifteen physiological and agronomic traits were collected, such as proline content (μmol.G1 fresh weight), glycine betaine (μmol.g1 fresh weight), total soluble sugars (μ mol.g1 fresh weight), total chlorophyll (mg g1 fresh weight), nitrate reductase activity ((NRA) (μ mol.g1 fresh weight hr1), potassium content (K +) (% g1 fresh weight), osmotic potential (MPa) together with named agronomic characteristics, plant height (cm), ear length (cm), number of plowed plants1, straw/plant weight (g) , 100-grain weight (g), seed index (g), days up to 75% bearing, days up to 75% maturity.Statistical analysis.The recorded data was subjected to analysis of variance to distinguish the superiority of the treatment units, and the LSD (least significant differences) test according to <0.1 and <0.5 % of probability level.
Nitrate reductase activity: Nitrate reductase activity showed significant negative correlations with total soluble sugars (r= -0.231*).However, significant and positive correlations were observed with total chlorophyll content (r= 0.335*).Total soluble sugar: Total soluble sugar revealed onsignificant and negative associations with observed total chlorophyll content% (r= -0.211 ns ).
Chlorophyll content (mg g -1 fresh wt.):Total chlorophyll content remains highly significant correlated with relative water content, seed index and significant for plant height, tillers per plant, spike length and nitrate reductase activity .

Discussion
The study of drought was one of the complex global physical and chemical processes in which severity occurs in the growth stage of plants (Khakwani et al., 2011).Correlation studies are essential to measure size and directional relationship with grain yield and related traits (Rajper et al., 2018).The correlation coefficient of yield and related traits, indicating an inherent association between the traits, is shown in Table 1.The results showed that the days to maturity and the days to growth predicted a significantly positive association with the height of the plant (cm) and the length of the ear (cm).(Nemat et al., 2015), also predicted a significant and positive correlation, which reflects that plant height (cm) and ear length (cm) will eventually increase with increasing days of sprouting and maturity.However, negative and positive associations were observed with grain weight (g), straw weight (g) and seed index (g), days at 75% forcing and days at 75% maturity, content Relative water%, potassium content, glycine betaine, nitrate reductase activity, plus total soluble sugar and % total chlorophyll.Similar results with a significant correlation with other detection traits and genotypes were also examined for other breeding programs (Habibpor et al., 2011).A negative correlation was also often found between performance under stress conditions and flowering date (Dodig et al., 2016).The grain yield of a variety depends on its yield components, since (Sheron et al., 1986) observed that plant height, ear length and kernels per ear are directly related to grain yield.Similarly (Shamsuddin, 1987) reported that ears per plant, kernels per ear, 1000 kernel weight, crop index, glume weight, and biological yield are directly related to wheat grain yield.According to another study of the components of durum wheat yield (Simane, 1993).The height of the plant (cm), the tiller plant-1 had negative and positive and significant and non-significant results for the characteristics tiller plant -1 , ear length, grain weight, straw weight and seed index.In dry tests, a positive and significant correlation was observed between grain yield and grain filling time, chlorophyll content, number of grains per ear, and ear weight.However, a negative and significant correlation was observed between grain yield and the number of days to drive (Hasan Kilic and Yagbasanlar, 2010).However, the association with physiological characteristics showed a negative and positive correlation with proline content, osmotic potential, relative water content, Potassium content, glycine betaine, nitrate reductase activity, total soluble sugar and total chlorophyll content.The length of the ear and the weight of the grain showed significant positive correlations with the seed index.However, both traits did not observe significant and positive correlations with grain weight.The observed physiological characteristics, negligible and negative correlations, were observed with proline, glycine betaine, nitrate remodeling activity, total soluble sugars and total chlorophyll content.The straw weight showed significant positive correlations with the seed index.The proline content had a significant and positive association with the osmotic potential, the potassium content, the betaine glycine, the total soluble sugar and the total chlorophyll content.However, in terms of relative water content, significant and negative correlations were observed with nitrate reductase activity.The proline content increases significantly under stress conditions.The positive correlation observed between grain yield and proline content under drought stress conditions shows that ultimately proline accumulation could be seen as a tool for effective selection of drought-tolerant genotypes (Mwadzingeni et al., 2016).The relative water content showed significant negative correlations with glycine betaine, total soluble sugars and potassium content.Potassium and glycine betaine showed significant and negative correlations with nitrate reductase activity.Total soluble sugar showed significant and negative associations with the total chlorophyll content%.

Conclusion
From the present study it was concluded that the ESW9525 showed better performance in all morphological and physiological traits, the correlation and the coefficient showed that the days to maturity and the days to growth predicted significant positive predictions related to the height of the plant (cm) and the length of the ear.Days to 75% heading and Days to 75% maturity showed negative and positive effects respectively osmotic potential, relative water content in% and total chlorophyll content in%.Plant height (cm) had negative and positive and significant with tiller plant -1 .Therefore, variety ESW9525 may be favorable for hybridization in order to produce a promising and drought tolerant wheat cultivar.