The Effect of GA3 and Salicylic Acid Combination on the Growth of Groundnut Sprout (Arachis Hypogaea L.) on Aluminum Stress

*Correspondence Address: nnoviani2812@gmail.com This study aimed to determine the influence of GA3 and salicylic acid on the germination and growth of Kelinci variety groundnut under aluminum stress. The research was conducted in the Botanical Laboratory of the Faculty of Mathematics and Natural Sciences, University of Lampung. This research was conducted in a 2x3 factorial experimental design. Factor A was AL (OH) 3 with two levels of concentration: 0% b/v and 5% b/v. Factor B was Growth Stimulant Substance (ZPT) with three levels of concentration: GA3 (0.1% w/v), salicylic acid (0.1% w/v), and GA3 and salicylic acid. The Tukey test determined the Main Effect, and the Simple Effect was determined with F-test at a significant level of 5%. It can be concluded that the mixture of GA3 solution and US solution was more effective than a single solution of GA3 or US.

Production can be increased using superior varieties and improving technical cultures, such as plant care, proper fertilization, and drainage systems. (Primandari, 2019;Sembiring et al., 2014). One of the reasons for the decline in groundnut production is the gynophore's inability to enter the soil, which causes the gynophore to fail to form pods (Hadi, 2017). Salicylic acid is an important signal in plant resistance used to impact resistance to disease (Primandari, 2019;AR Putri, 2017). Plants' salicylic acid responses to pathogenic attacks as a form of defense (Afkar et al., 2019;AOT Putri et al., 2016). Salicylic acid is a hormone naturally produced by plants (Novita & Siregar, 2015;Yulianti, 2012). Salicylic acid is a phenolic compound with a tolerance effect against abiotic stress (EFENDI, 2016).

METHOD
This research was conducted at the Botanical Laboratory, Faculty of Mathematics and Natural Sciences, the University of Lampung, from November to December 2018. The equipment used in this study were plastic trays, plastic cups, filter paper, labels, tissues, rubber bands, plastic, beaker glass, Erlenmeyer, measuring cup, volume pipette, drop pipette, test tube, mortar, crucible rack, digital scale, centrifuge, oven, UV spectrophotometry, knife, scissors, and ruler. The materials used in this study were groundnut seeds obtained from the Lampung Province Seed Center, Al (OH) 3, gibberellin hormone (GA3), salicylic acid, alcohol, and distilled water. This research was conducted using a 2 x 3 factorial experimental design. Factor A was Al (OH) 3 with the concentration levels of 0% w/v and 0.5% w/v. There were 48 normally germinated seeds were selected. The container used for the sprouts was a plastic cup. A total of 24 plastic cups were washed and wiped dry. They were then labeled with the treatment and repeat combination notation. Furthermore, the plastic cups were coated with tissue and filter paper moistened with 0.1 ml of GA3, 5 ml of salicylic acid, a mixture of 0.1 ml of GA3, and a mixture of 0.1 ml of salicylic acid. Each plastic cup contained two sprouts. The germination variable was observed for 7 days after the treatment.

RESULTS AND DISCUSSION
Each treatment combination was repeated four times so that the number of experimental units was 24. This study's variables were germination power, shoot length, fresh weight, dry weight, relative moisture content, and chlorophyll a, b, and total. This study's parameters were all mean (µ) values of all the growth variables of groundnut sprouts.
The Al (OH) 3 solution was made from 0.5 grams of Al (OH) 3 powder dissolved in 100 ml of distilled water to obtain a concentration of 0.5% w/v. Then, the GA3 solution was made from 0.1 gram of GA3 powder dissolved in 100 ml of distilled water to obtain a concentration of 0.1% w/v. Likewise, the salicylic acid solution was made from 0.1 gram of salicylic acid powder dissolved in 100 ml of distilled water to obtain a concentration of 0.1% w/v. The seeds were selected by soaking them in distilled water for 10 minutes. The floating seeds and wastes were removed, while the sinking seeds were taken to be germinated.
The selected seeds were then soaked in three levels, namely, GA3, Salicylic Acid, and mixtures of GA3 + Salicylic Acid. Also, there were three levels of concentration of Al (OH) 3, namely Al (OH) 3 5% w/v + GA3 , Al (OH) 3 5% w/v + Salicylic Acid, and Al (OH) 3 5% w/v + GA3 + Salicylic Acid for 24 hours. The soaked groundnut seeds were spread out into six plastics covered with tissue paper and moistened with distilled water for germination. There were 600 deeds used to be placed in trays containing 100 seeds each. The effect of salicylic acid, GA3, and the combination of salicylic acid and GA3 is shown in Figure 1. Aluminum toxicity (Al-toxicity) is one of the main factors limiting plant growth and development in many acid soils. The plasma membrane of root cells, especially the root apex, appears to be the main target of Al-toxicity. However, the strong interaction of Al3 +, the main toxic form of Al, with the oxygen donor ligands (proteins, nucleic acids, and polysaccharides) inhibits cell extension, cell division, and transport (Koentjoro & Biotech, 2020).
The results of this study indicated that under normal growth conditions, GA3 + SA was more effective in encouraging seed germination seeds compared to salicylic acid and GA3. Likewise, SA was more effective than GA3 in encouraging the seed germination. GA3 + AS was more effective than SA and GA3 in encouraging the seed germination. GA3 was more effective than the SA in encouraging the seed germination (Sofiana & Syaban, 2017). The germination success depends on two important physiological processes: the absorption of water by the seeds (imbibition) and the hydrolysis of starch to glucose as the main substrate in the respiration process. The α amylase enzyme catalyzes the hydrolysis of starch, while glucose is the main energy source for the germination process.
The simple effect analysis showed that at the GA3 level, Al (OH) 3 treatment decreased the average shoot length. In salicylic acid treatment, there was no significant shoot length difference between the control and Al (OH) 3. Likewise, at the level of GA3 + AS, there was no significant difference in the mean shoot length between control and Al (OH) 3.  The effect of salicylic acid, GA3, and the combination of salicylic acid and GA3 on the shoot length of Kelinci variety groundnut under aluminum hydroxide stress is shown in Figure 2. The Levene test at a significant value of 5% found that the population variety was homogeneous (attachment 1 p> 0.05). The results showed that aluminum had no significant effect on shoot length, while ZPT significantly affected shoot length. The interaction between aluminum and ZPT had a significant effect on shoot length.  Based on the interaction between Al (OH) 3 and GA3, salicylic acid tended to reduce the average length of groundnut shoots. In contrast, the interaction between Al (OH) 3 tended to increase the shoot length. The effect of salicylic acid, GA3, and the combination of salicylic acid and GA3 on the fresh weight of Kelinci variety groundnuts under aluminum hydroxide stress is shown in Figure 4. The Levene test at a 5% significant level showed that ZPT had a significant effect on sprouts' fresh weight. However, Al (OH) 3 and its interaction with ZPT had no significant effect on sprouts' fresh weight.

Figure 4. Main Effect Analysis of ZPT on Fresh Weight of Kelinci varieties Groundnut Sprouts
The main effect analysis showed that groundnut sprouts' response to GA3, salicylic acid, and GA3 + salicylic acid was relatively different. Salicylic acid had a higher stimulating effect than GA3 and GA3 + salicylic acid. Fresh weight is determined by the dry weight and relative moisture content of the sprouts. The water absorption rate by the roots and the rate of transpiration by the leaves determine the fresh weight of sprouts (Istiqhomah et al., 2019;Nio & Torey, 2013;Prasetya et al., 2019). The allocation of food reserves from seeds or endosperm determines the dry weight of the plant. The results showed that the effect of ZPT did not depend on growing conditions. The fresh weight of sprouts did not differ relative to normal ZPT growth and aluminum stress conditions. SA was relatively better at stimulating water uptake by roots than GA3 and GA3 + SA (Kartawijaya, 2014).
The effect of ZPT and its interaction with Al (OH) 3 on Kelinci variety groundnut sprouts' dry weight is shown in Table 4. The Levene test at the 5% significant level showed that the population variety was homogeneous. Uniform analysis at the 5% significant level showed that ZPT, Al (OH) 3, and their interactions had no significant effect. The effect of ZPT and its interaction with Al (OH) 3 on Kelinci variety groundnut sprouts' relative moisture content is shown in Table 5. The Levene test at the 5% significant level showed that the population variance was homogeneous. Uniform analysis at the 5% significant level showed that ZPT, Al (OH) 3, and their interactions had no significant effect. The aluminum stress condition did not affect the dry weight and relative moisture content of groundnut sprouts. Therefore, aluminum toxicity did not affect the allocation of food reserves. Likewise, the same phenomenon was found in the relative moisture content.

CONCLUSION
Based on the analysis, it can be concluded that a mixture of GA3 solution and SA solution was more effective than a single GA3 solution or SA solution in overcoming Al-toxicity on germination and growth of Kelinci variety groundnut sprouts. It is suggested to research the effects of a mixture of GA3 and SA solutions on germination and other sprouts' growth.