Characterization of M8 Wheat Mutant Adaptability to Low Land

The wheat requirement in Indonesia is still fulfilled by import, which increases annually. To reduce the import dependence, Indonesia is required to elevate the domestic wheat production appropriate to the Indonesian agroclimatic condition by wheat plant breeding mutation. This study was aimed to characterize several mutant wheat commodities, that are adaptive to lowland condition. The experiment was arranged in a completely randomized block design with 16 observed-wheat genotypes (G). The wheat genotypes used were: 1) (G1) N1 200 2.4.B.6, 2) (G2) N 200 2.3.3, 3) (G3) N 200 2.5.2, (G4) N 350 3.6.2, (G5) N 350 3.7.1, (G6) N 300 3.6.1, (G7) N 350 3.1.3, (G8) N 250 3.7.1, (G9) M 200 1.7.1, (G10) S 300 7.9.1, (G11) S 300 2.1, (G12) D 200, and several comparative varieties, such as (G13) Guri-3 , (G14) Selayar , (G15) Nias , and (G16) Dewata . The results obtained that the lowland-adapted M8 wheat mutant with high productivity level was found in N 200 2.4.B.6 (2.75 t.ha -1 ), N 200 2.3.3 (2.69 t.ha -1 ), and D 350 3.6.2 (2.35 t.ha -1 ). Characters with the highest heritability level were number of tillers, number of productive tillers, seed weight per panicle, and production. Meanwhile, characters, that were correlated with production, were plant height, number of tillers, number of productive tillers, harvesting age, seed-filling period, number of spikelets per panicle, percentage of empty florets, number of seeds per panicle, and seed weight per panicle


A. Introduction
analysis was performed by analysis of variance with the Least-Significant Different (LSD) test at a 0.05 confidence level. To find out the relationship between the characters, regression and correlation studies were carried out, while the genetic diversity of mutant genotypes was carried out by heritability analysis

C. Result and Discussion
The LSD test results from Table 1 indicate that the N200.2.4.B.6 (g1) obtained the highest plant height (57.00 cm), which was significantly different from the comparative varieties, namely Guri-3 (a) and Selayar (b). Based on the number of tillers, the N 200 2.4.B.6 (g1) also had the most tillers (5.60 tillers) and was significantly different from the comparative varieties, namely Selayar (b), Nias (c), and Dewata (d), while the number of productive tillers showed that the N 200 2.4.B.6 (g1) had the most productive tillers (4.53 tillers) and was significantly different from the comparative varieties, such as Guri-3 (a) and Dewata (d). The number of productive tillers was affected by an environmental factor, namely air temperature, whereas higher air temperature tended to inhibit the number of productive tiller growth. This condition followed Andriani & Isnaini (2011), that the number of tillers depended on the variety and environmental conditions. Each tiller has the potential to produce one panicle. The number of tillers importantly contributes to the harvesting product. This condition was similar to Rachmadani, S., Damanhuri, D., & Soetopo, L. (2017), that the number of tillers could directly affect the product per plant as part of the selection criteria to gain a highly potential wheat genotype. The higher number of productive tillers, the more seed produced in the plants.
Based on the LSD test results from Table 2, the N 350 3.1.3 (g7) obtained the fastest flowering day (43.33 DAP) and was significantly different from the comparative varieties, namely Guri-3 (a) and Selayar (b), while seed-filling rate showed that the N 200 2.4.B.6 (g1) obtained the fastest seed filling (27.47 days) and was significantly different from the comparative varieties, namely Guri-3 (a), Selayar (b), and Dewata (d). The flowering day in the wheat plant can also be affected by the environment, mainly temperature. High temperatures can accelerate the flowering process. Wheat planted in lowland flowers faster than in highland (<400 asl). This condition was caused by the lowland environmental condition is more supportive for wheat growth, based on the temperature, humidity, and sunlight level. Wahyu, Y., Samosir, A. P., & Budiarti, S. G (2013) performed a study on wheat and stated that the flowering day of wheat in the lowland was about 43-70 DAP. A faster harvesting day was thought due to temperature stress in the lowland. Besides environmental conditions, the factor of land height can also affect the flowering day and harvesting period. Wahyu et al (2013) stated that extremely high air temperatures could affect the harvesting period in several wheat varieties in the low-elevated area.  The LSD test results from Table 3 present that the N 250 3.7.1 (g8) obtained the highest panicle length (8.47 cm) and was significantly different from the comparative varieties of Guri-3 (a), Selayar (b), and Dewata (d). The number of spikelets per panicle data presents that the N 200 2.4.B.6 (g1) has the highest value and (13.20 spikelets) and was significantly different from the comparative varieties of Guri-3 (a) and Nias (c). Furthermore, the number of seeds per panicle data indicates that the N 200 2.4.B.6 (g1) had the highest value (28.13 seeds) and was significantly different from the comparative varieties.
Panicle length is a product component that has a direct connection to the number of spikelets. Based on Kirby (2002), the longer panicle found, the more spikelets formed as a potential of a greater number of seeds produced. The panicle length also showed an interaction after the temperature stress treatment (Syuryawati, Rahmi YA, Zubachtirodim, 2007).  The LSD results in Table 4 present that the N 200 2.4.B.6 (g1) obtained the greatest number of seeds per panicle (28.88 seeds) and was significantly different from the comparative varieties of Guri-3 (a), Selayar (b), and Dewata (d). The seed weight per panicle data indicates that the N 200 2.4.B.6 (g1) obtained the highest weight (0.79 g), as also found in the weight of 1000 seeds (28.84 g), which was significantly different from all comparative varieties, while the production value showed that the N 200 2.4.B.6 (g1) was the most productive variety (2,75 t.ha -1 ) and significantly different from all comparative varieties. Commonly, one spikelet per wheat panicle has three florets, each of which is filled with one wheat seed. Therefore, the greater number of spikelets, the greater number of florets formed. This condition was similar to Wahyu et al. (2013), who stated that a greater number of empty florets per panicle represents a lower number of seeds produced per panicle.
The increased number and percentage of empty florets in the lowlands was caused by the drought or no rainy weather during the seed filling period, followed by the increased temperature that caused the pollen development failure and seed production inhibition. The number of empty florets affects directly the decreased seed weight per panicle and wheat production per grove. The percentage of empty florets in the lowest value is quite tolerable, following Nur (2013), who mentioned that the genotype selection with low empty floret level should be performed to obtain a highly temperature-tolerant genotype in lowland cultivation.  In Table 5, the highest heritability level is presented from the number of productive tillers' character (91.28%). Heritability level depends on the genotype and environment variance. Heritability is a variance proportion caused by the genetic factors against the phenotype variance. Heritability level is one of the genetic parameters considered for character selection (Wirnas, D., I. Widodo, Sobir, Trikoesoemaningtyas, D. Sopandie , 2006;Suharsono & Jusuf, 2009;Sungkono Trikoesoemaningtyas, D. Wirnas, D. Sopandie, 2009;Syukur M., S. Sujiprihati, A. Siregar, 2010;Yunianti R., S. Sastrosumarjo, S. Sujiprihati, M.Surahman, S.H. Hidayat, 2010;Barmawi et al., 2013). Based on the highest heritability level, characters that can be considered as selection characters to choose the best family are the number of tillers, number of productive tillers, seed weight per panicle, and production.
Correlation denotes the amount of relationship occupied in the observed parameters. The correlation coefficient analysis results from Table 6 indicate the correlation of productivity character with other characters. This condition means that plant height, number of tillers, number of productive tillers, chlorophyll index, harvesting period, seed-filling period, number of spikelets per panicle, percentage of empty florets, production per grove, number of seeds per panicle, seed weight per panicle are significantly correlated with the production, as each of which has the correlation values of 0. 39, 0.75, 0.78, 0.56, -0.33, -0.37, 0.33, -0.53, 0.99, 0.58, and 0.62, respectively. Correlation analysis is an overview of the kinship level between one character to the others, but the value of correlation cannot explain the causal relationship of the kinship level among characters. Therefore, the role of cross-print analysis is important to elaborate the correlation coefficient. The results of the cross-print analysis can describe how significant the direct and indirect effects of a character to the main character (Rohaeni & Permadi, 2012). The use of correlation analysis and cross-print analysis in determining the selection character has also been performed in many studies, including Milligan   Penicle Lenght

D. Conclusion
The results showed that the genotypes of M8 wheat mutants in lowland obtained the highest production in the N 200 2.4.B.6 (2.75 t. ha-1), N 200 2.3.3 (2.69 t.ha -1 ) and N 350 3.6.2 (2.35 t.ha -1 ). Characters that had high heritability level in M8 wheat mutant were number of tillers, number of productive tillers, weight seeds per panicle, and production. Furthermore, characters that were highly correlated with production were plant height, number of tillers, number of productive tillers, harvesting period, seed filling period, number of spikelets per panicle, percentage of empty florets, number of seeds per panicle, and seed weight per panicle.