Perakitan Varietas Hibrida Jagung Tropika Tipe Dent (Zea mays L.) untuk Industri Pangan

Abstract

Jagung hibrida tipe dent (Zea mays L.) merupakan komoditas penting untuk industri pangan karena memiliki keunggulan rendemen penggilingan dan kandungan nutrisi. Kebutuhan jagung tipe dent didominasi oleh impor sehingga perakitan varietas hibrida jagung tropika tipe dent fokus industri pangan menjadi salah satu solusi untuk mengurangi impor jagung industri. Penelitian ini bertujuan memperoleh informasi kombinasi persilangan potensial untuk direkomendasikan sebagai varietas. Penelitian ini terdiri dari tiga percobaan utama menggunakan materi genetik hasil silang tunggal dari enam tetua galur inbrida (BCY, ERC24, G102612D, GLT226, MSM53, P2) dengan rancangan persilangan setengah dialel metode Griffing IV hasil program pemuliaan Balai Penelitian Tanaman Serelia (Balitsereal). Percobaan pertama, yaitu stabilitas hasil dan keragaan agronomis di delapan lingkungan. Percobaan kedua, yaitu evaluasi daya gabung dan heterosis yang dilaksanakan di dua lingkungan yang merupakan bagian dari delapan lingkungan uji multilokasi. Percobaan ketiga, yaitu keragaman morfologi biji dan sifat fisiko-kimia tepung jagung menggunakan materi genetik dari percobaan kedua. Informasi dari setiap percobaan digunakan sebagai bahan pertimbangan seleksi untuk rekomendasi varietas dengan metode seleksi indeks terboboti. Percobaan pertama bertujuan untuk (1) mempelajari stabilitas hasil menggunakan beberapa parameter stabilitas, (2) mempelajari keragaan agronomis di delapan lingkungan, dan (3) mengidentifikasi hibrida dengan potensi hasil tinggi dan stabil. Percobaan dilaksanakan pada tahun 2021 dan 2022 di Sinjai, Gowa, Maros, Tomohon, Ponorogo, dan Malang. Sepuluh kombinasi persilangan dan dua varietas pembanding (RK457 dan RK57) sebagai materi genetik uji. Percobaan menggunakan rancangan kelompok lengkap teracak (RKLT) dengan tiga ulangan di setiap lingkungan dan analisis ragam gabungan model campuran (hibrida faktor tetap dan lingkungan faktor acak). Faktor lingkungan, hibrida, dan interaksi GxL merepresentasikan 81,89%, 6,59% dan 11,51% total keragaman nilai Yi, secara berturut-turut. Hibrida G09 dan G10 stabil berdasarkan parameter stabilitas Kang index stability, Francis-Kannenberg, Finlay-Wilkinson, dan Eberhart-Russell. SIN21 (E3) diidentifikasikan lingkungan representatif dan informatif. Hibrida G04, G06, dan G09 terseleksi berdasarkan analisis GGE biplot karena Yi tinggi, relatif stabil, berlokasi di sekitar zona genotipe ideal, dan beradaptasi luas di semua jenis elevasi. Hibrida G01, G05, dan G08 terseleksi untuk konsistensi tipe biji dent. Variasi karakter kuantitatif didominasi faktor lingkungan. Lingkungan dataran tinggi (>500 m dpl) memberikan respon nyata lebih tinggi untuk karakter , umur berbunga betina dan jantan, dan bobot tongkol panen dibandingkan lingkungan dataran rendah. Percobaan kedua bertujuan untuk (1) evaluasi daya gabung dan heterosis hibrida dan (2) mempelajari asosiasi antar parameter. Percobaan dilaksanakan pada tahun 2021 dan 2022 di Ponorogo dan Maros. Enam galur inbrida tetua, 15 kombinasi persilangan, dan dua varietas pembanding (RK457 dan RK57) sebagai materi genetik uji. Percobaan menggunakan RKLT dengan tiga ulangan di setiap lingkungan dan rancangan persilangan setengah dialel metode Griffing IV. Nilai Yi tetua antara 0,92 ton ha-1 sampai 2,55 ton ha-1. Berdasarkan nilai interaksi DGUxL maka tetua donor terseleksi spesifik lingkungan uji, yaitu BCY dan P2 untuk sudut daun dan GLT226 untuk bobot 1000 biji di lingkungan PON21 serta ERC24 untuk sudut daun di lingkungan MRS22. Berdasarkan nilai interaksi DGKxL maka kombinasi persilangan terseleksi spesifik lingkungan uji, yaitu GLT226 x MSM53 (G14) untuk sudut daun di lingkungan PON21 serta MSM53 x BCY (G05) untuk sudut daun dan GLT226 x BCY (G12) untuk jumlah biji per baris di lingkungan MRS22. Kombinasi persilangan BCY x G102612D (G01) memiliki nilai mid-parent heterosis dan heterobeltiosis lebih tinggi dibandingkan hibrida lainnya untuk karakter Yi. Parameter nilai tengah Yi hibrida berkorelasi positif terhadap DGU tetua jantan, DGK, dan heterobeltiosis. Kompatibilitas tetua persilangan merupakan salah satu faktor kesuksesan hibridisasi. Percobaan ketiga bertujuan untuk (1) mempelajari morfologi biji dan sifat fisiko-kimia tepung jagung dan (2) seleksi tepung jagung hibrida berdasarkan kandungan nutrisi dan prefrensi konsumen untuk industri pangan. Materi genetik uji menggunakan 15 kombinasi persilangan dan empat varietas pembanding (RK457, RK57, BISI18, dan NASA29). Dimensi biji G07 dan G13 nyata lebih pipih dibandingkan NASA29. Rendemen tepung 40/0 mesh G04, G05, dan G10 nyata lebih tinggi dibandingkan semua varietas pembanding. Karakteristik biji yang meningkatkan rendemen tepung, memiliki kecenderungan tipe dent, bobot 1000 biji lebih ringan, bobot jenis dan densitas kamba yang lebih rendah serta dimensi biji yang pipih. Hibrida tipe semi-dent dan semi-flint lebih unggul pada kuantitas biji, sedangkan tipe dent pada kemampuan hasil penggilingan kering. Tepung jagung hibrida tipe dent mengandung karbohidrat total dan karbohidrat terlarut nyata lebih tinggi serta lemak kasar nyata lebih rendah dibandingkan tipe semi-dent dan semi-flint. Berdasarkan analisis GT biplot, hibrida tipe dent unggul kadar pati, karbohidrat total, dan karbohidrat terlarut. Hibrida tipe semi-dent unggul kadar air, protein kasar, dan abu total. Hibrida tipe semi-flint unggul kadar lemak kasar dan serat kasar. Klaster-2 didominasi oleh hibrida tipe dent dengan kadar karbohidrat total dan karbohidrat terlarut nyata lebih tinggi dibandingkan hibrida klaster-1. Warna tepung G05 lebih disukai oleh responden. Ideotipe hibrida yang direkomendasikan sebagai calon varietas: berdaya hasil tinggi, keragaan agronomis yang baik di berbagai lingkungan, kemampuan hasil penggilingan kering yang baik, dan kadar pati tinggi. Kombinasi persilangan P2 x G102612D (G04), MSM53 x BCY (G05), dan ERC24 x G102612D (G10) terseleksi karena nilai indeks bernilai positif dan lebih tinggi dibandingkan rataan total. Hibrida terseleksi memiliki perbedaan keunggulan adaptabilitas, resistensi penyakit, kandungan nutrisi tepung dan potensi produktivitas pati. Hibrida G04 dan G05 memiliki tipe biji dent serta G10 bertipe semi-dent. Potensi produktivitas pati G04, G05, dan G10 sebesar 6,54 ton ha-1, 6,44 ton ha-1, dan 6,35 ton ha-1, secara berturut-turut. Hibrida terseleksi bermanfaat sebagai calon varietas fokus industri pangan untuk meningkatkan daya saing agroindusti jagung nasional.

Dent corn hybrid (Zea mays L.) is commonly used for food industries because it has good milling abilities and nutritional values superiorities. The demand of dent corn in Indonesia is mostly fulfilled by import, so developing tropical dent corn hybrid varieties for food industries is one potential solution for reducing industrial corn import. This research aimed to obtain information on potential hybrids to be recommended for variety candidates. This research consisted of three main experiments and the plant materials derived from single crossing six inbred lines (BCY, ERC24, G102612D, GLT226, MSM53, P2) with Griffing IV diallel mating design from the breeding program of Indonesian Cereals Research Institute (ICERI). The first experiment was on yield stability and agronomic performances in eight environments. The second experiment was on combining ability and heterosis evaluation which was conducted in two environments from the first experiment. The third experiment was on variability of kernel morphological and flour physico-chemical properties using the plant materials from the second experiment. The information from each experiment is useful for formulating a recommendation of variety candidates by using weighted index selection. The first experiment aimed to (1) elucidate the yield stability using several parameters, (2) elucidate agronomic performance in eight test environments, and (3) identify tropical dent-type maize hybrids with high and stable yield potential. The trials were conducted in 2021 and 2022 in Sinjai, Gowa, Maros, Tomohon, Ponorogo, and Malang. Ten hybrids and two check varieties (RK457 and RK57) were used as plant materials. The experiments were conducted in a randomized complete block design (RCBD) with three replications in each environment. A combined analysis of variance was performed with a mixed model (environment as a random effect and hybrid as a fixed effect). The environment, hybrid, and GxE interaction factors represented 81.89%, 6.59% and 11.51% of the total variation of Yi, respectively. G09 and G10 hybrids were stable according to the Kang yield stability index, Francis-Kannenberg, Finlay-Wilkinson, and Eberhart-Russell parameters. SIN21 (E3) was identified as a representative and discriminative environment. G04, G06, and G09 were selected according to GGE biplot analysis due to having high Yi, relatively stable, located around ideal genotype zone, and widely adapted in all elevations. G01, G05, and G08 hybrids were selected for dent-type consistency. The variation of quantitative characters was dominantly due to the environmental factor. Highland environment (>500 m asl) resulted in Yi , tasseling, silking, and harvest weight significantly higher compared to lowland. The second experiment aimed to (1) evaluate the combining ability and heterosis of hybrids and (2) elucidate the association among parameters. The trials were conducted in 2021 and 2022 in Ponorogo and Maros. Six inbred lines, 15 crosses (half diallel), and two check varieties (RK457 and RK57) were used as plant materials. The experiments were conducted in RCBD with three replications following the Griffing IV diallel mating design. The Yi values of parents varied from 0,92 ton ha-1 to 2,55 ton ha-1. According to the GCAxE interaction, BCY and P2 were selected for erect leaf and GLT226 for 1000-kernel weight as the best donors specific at PON21. ERC24 was selected as the best donor for erect leaf at MRS22. According to the SCAxE interaction, GLT226 x MSM53 (G14) was selected for erect leaf specific at PON21. MSM53 x BCY (G05) was selected for erect leaf and GLT226 x BCY (G12) was selected for the number of kernels per row specific at MRS22. The yield heterosis of BCY x G102612D (G01) was the highest. The yield heterosis was positively correlated to ear weight and yield percentage. The hybrid mean yield was positively correlated with male parents GCA, SCA, and heterobeltiosis. The compatibility of parents was the one of success factors for hybridization. The third experiment aimed to (1) study kernel morphology and corn flour physico-chemical properties and (2) hybrid selection based on corn flour nutritional values and consumer preferences for food industries. Plant materials were 15 crosses and four check varieties (RK457, RK57, BISI18, and NASA29). The experiments were conducted in RCBD and balanced incomplete block design (BIBD). The sphericity of G07 and G13 were significantly lower compared to NASA29. The 40/0 mesh corn flour yields of G04, G05, and G10 hybrids were significantly higher compared to all check varieties. Grain characteristics that are related to increase in corn flour yields were dent type, lighter 1000-grain weight, lower sphericity, lower kernel density, and kernel bulk density. Semi-dent and semi-flint hybrids were superior in kernel quantity, whereas dent hybrids on dry-milling abilities. Total and soluble carbohydrate contents of dent corn flour hybrids were significantly higher and crude fat content was significantly lower compared to semi-dent and semi-flint corn flour hybrids. According to polygon GT biplot analysis, the dent hybrids had superiority in starch, total carbohydrate, and soluble carbohydrate contents. The semi-dent hybrids had superiority in moisture, crude protein, and total ash contents. The semi-flint hybrids had superiority in crude fat and crude fiber contents. Hybrids in cluster-2 were dominated by dent type and were selected as potential hybrids due to had total and soluble carbohydrate contents significantly higher. The corn flour color of G05 was preferred by respondents. The main characteristics of hybrid ideotypes for variety candidates were high yielding, good agronomic performances, good dry-milling abilities, and high starch content. P2 x G102612D (G04), MSM53 x BCY (G05), and ERC24 x G102612D (G10) hybrids were selected due to having a positive total index and higher compared to the grand mean. The selected hybrids had different superiorities of adaptability, disease resistance, nutritional values, and starch potential productivity. G04 and G05 hybrids were dent type, and G10 was semi-dent type. The starch potential productivity of G04, G05, and G10 were 6,54 ton ha-1, 6,44 ton ha-1, and 6,35 ton ha-1, respectively. The selected hybrids are useful for variety candidates for food industries focused that could increase national corn agroindustrial competitiveness.