| dc.description.abstract | Okra (Abelmoschus esculentus L. Moench) termasuk dalam famili
Malvaceae, merupakan tanaman hortikultura yang memiliki nilai ekonomi dan
farmakologis tinggi. Selain dikonsumsi sebagai sayuran, okra dikenal sebagai
sumber senyawa bioaktif seperti flavonoid, fenolik, dan senyawa antioksidan
lainnya yang mempunyai fungsi fisiologis dan bermanfaat bagi kesehatan. Oleh
sebab itu selain produktivitas tinggi, program pemuliaan tanaman okra diarahkan
untuk tujuan senyawa fungsional tinggi. Studi genetik senyawa fungsional pada
okra perlu dipelajari sebagai landasan awal program pemuliaan tersebut.
Penelitian terdiri atas lima percobaan, yaitu: Percobaan pertama adalah
karakterisasi kandungan biokimia, karakter kuantitatif dan kualitatif genotipe
okra yang bertujuan untuk memperoleh informasi keragaman pada genotipe okra
yang akan dijadikan sebagai calon tetua dalam kegiatan pembentukan populasi
untuk kegiatan penelitian selanjutnya. Percobaan kedua yaitu uji kandungan
biokimia pada beberapa fase panen muda buah okra yang bertujuan untuk
memperoleh fase panen muda yang tepat untuk kandungan biokimia tertinggi.
Percobaan ketiga yaitu studi pewarisan sifat kandungan biokimia dan karakter
kuantitatif pada okra yang bertujuan untuk memperoleh informasi studi pewarisan
sifat. Percobaan keempat yaitu analisis daya gabung umum dan khusus
kandungan biokimia dan karakter kuantitatif pada genotipe tetua dan hasil
persilangan okra yang bertujuan untuk memperoleh informasi daya gabung
kandungan biokimia dan karakter kuantitatif. Percobaan kelima yaitu keragaan
calon varietas unggul hibrida okra yang bertujuan memperoleh informasi
keragaan hibrida genotipe okra hasil persilangan.
Percobaan pertama menghasilkan perbedaan baik pada kandungan
biokimia, karakter kuantitatif dan kualitatif. Karakter buah merupakan karakter
kuantitatif yang paling beragam. Berdasarkan hasil analisis cluster menunjukkan
bahwa genotipe okra dikelompokkan menjadi 3 cluster baik untuk kandungan
biokimia maupuk karakter kuantitatif dan kualitatif. Berdasarkan hasil analisis ini
terpilih 8 genotipe yaitu Naila IPB dengan keunggulan tinggi kandungan
flavonoid dan antioksidan DPPH, Green Velvet unggul pada keragaan vegetative,
Clemson memiliki keunggulan pada panjang buah, F7 ClemsonxStripe-3-23-4
27-50 unggul pada karakter jumlah lokul. Genotipe okra merah unggul pada
aktivitas antioksidan DPPH, C127 memiliki keunggulan pada umur panen yang
genjah serta Red Hill Country unggul pada karakter inhibisi enzim
alfaglukosidase, bobot dan diameter buah. Tidak ada keterkaitan antara
komponen produksi dengan karakter biokimia kecuali umur berbunga dan umur
panen.
Percobaan kedua menunjukan bahwa genotipe dan fase panen
menunjukkan interaksi sehingga respon delapan genotipe uji berbeda-beda pada
masing-masing fase terhadap kandungan biokimia. Karakter kandungan total
fenolik, flavonoid dan aktivitas antioksidan metode FRAP menyatakan fase
panen 6 HSA paling tinggi menghasilkan kandungan biokimia tersebut.
Sedangkan pada aktivitas antioksidan metode DPPH fase 6 dan 9 HSA
menghasilkan kandungan yang hampir sama. Selanjutnya untuk karakter inhibisi
enzim alfaglukosidase maksimal dihasilkan oleh okra dengan fase panen 9 HSA.
Genotipe Okra Merah unggul pada karakter fenolik dan antioksidan FRAP.
Genotipe Red Hill Country unggul pada karakter flavonoid, antioksidan DPPH
dan FRAP. Naila IPB unggul pada karakter antioksidan DPPH, serta F7
ClemsonxStripe-3-23-4-27-50 unggul pada karakter fenolik, antioksidan DPPH,
dan inhibisi enzim alfaglukosidase. Hasil penelitian ini memperkuat bukti bahwa
pemilihan waktu panen dapat dioptimalkan untuk tujuan tertentu, baik untuk
potensi antioksidan maupun antidiabetik.
Percobaan ketiga menunjukkan bahwa semua karakter komponen hasil
dan hasil tidak memiliki peranan interaksi gen kecuali jumlah buah dan umur
panen. Karakter antioksidan metode DPPH dan FRAP serta inhibisi enzim
alfaglukosidase tidak memiliki peranan interaksi gen. Terdapat pengaruh aksi gen
aditif dan dominan pada jumlah cabang, diameter buah, jumlah buah dan umur
panen. Pengaruh over dominansi dihasilkan oleh karakter jumlah buku, jumlah
cabang, jumlah buah, umur panen, produktivitas, total fenolik, total flavonoid,
aktivitas antioksidan DPPH dan FRAP. Semua karakter komponen hasil dan hasil
dikendalikan oleh satu kelompok gen kecuali karakter panjang buah. Selain itu,
semua karakter kandungan biokimia dikendalikan oleh dua kelompok gen. Nilai
duga heritabilitas arti luas (h2bs) pada karakter komponen hasil, hasil dan
kandungan biokimia menunjukkan kategori luas. Nilai duga heritabilitas arti
sempit (h2ns) kategori tinggi dihasilkan oleh karakter bobot per buah, panjang
buah dan diameter buah serta semua karakter kandungan biokimia.
Percobaan keempat menunjukkan bahwa Tetua F7 memiliki daya gabung
umum terbaik pada karakter jumlah buku, jumlah cabang, jumlah buah, dan
inhibisi enzim alfaglukosidase. Tetua RHC memiliki daya gabung umum terbaik
pada karakter bobot per buah, diameter buah, dan aktivitas antioksidan FRAP.
GV merupakan tetua dengan nilai DGU terbaik pada panjang buah dan umur
panen. Selanjutnya tetua OKM merupakan tetua dengan nilai daya gabung umum
terbaik untuk total fenolik dan flavonoid serta aktivitas antioksidan DPPH.
Hibrida F7 x Nai menghasilkan nilai daya gabung khusus tinggi pada karakter
jumlah buah dan produktivitas, kombinasi persilangan OKM x Nai menghasilkan
daya gabung khusus terbaik pada karakter panjang buah dan bobot buah. Hibrida
GV x F7 menghasilkan nilai daya gabung khusus tinggi pada umur panen dan
inhibisi enzim alfaglukosidase serta kombinasi RHC x OKM menghasilkan daya
gabung khusus tinggi pada total fenolik dan antioksidan DPPH.
Percobaan kelima menunjukkan bahwa Hibrida F7xNai memiliki
keunggulan pada jumlah buku, jumlah cabang, jumlah buah, produktivitas dan
inhibisi enzim alfaglukosidase tinggi. Sehingga hibrida F7xNai
direkomendasikan sebagai hibrida dengan produktivitas dan memiliki efek
antidiabetes tinggi, sedangkan hibrida RHCxOKM dan resiprokalnya
direkomendasikan menjadi hibrida dengan kandungan polifenol dan kapasitas
antioksidan paling baik dibandingkan hibrida lainnya. Keragaan warna buah dari
hibrida menunjukkan warna ungu lebih dominan dibandingkan warna hijau.
Karakter warna buah pada generasi F1 menjadikan warna sebagai penanda visual
(visual marker) yang sangat berguna dalam proses seleksi awal pemuliaan. | |
| dc.description.abstract | Okra (Abelmoschus esculentus L. Moench) is a horticultural crop
belonging to the Malvaceae family with high economic and pharmacological
value. Okra is consumed as a vegetable and is known as a source of bioactive
compounds, such as flavonoids and phenolic compounds, which have
physiological functions and health benefits. Therefore, okra breeding programs
focus on biofortification in addition to high productivity. Conducting genetic
studies of functional compounds in okra is necessary to establish a foundation for
such breeding programs.
The study consisted of five experiments. The first experiment involved
characterizing the biochemical content and quantitative and qualitative
characteristics of okra genotypes. This experiment aimed to obtain information
on the diversity of okra genotypes that would be used to form populations for
further research activities. The second experiment tested the biochemical content
at various stages of young okra fruit harvest to identify the optimal harvest stage
with the highest biochemical content. The third experiment studied the
inheritance of biochemical content and quantitative characteristics in okra to
obtain information on how these traits were inherited. The fourth experiment
analyzed the general and specific combining abilities of the biochemical content
and quantitative characteristics of the parent genotypes and okra crossbreeds to
obtain information about their combining abilities. The fifth experiment
examined the performance of superior okra hybrid candidate varieties.
The first experiment revealed differences in biochemical content and
quantitative and qualitative characteristics. Fruit characteristics were the most
diverse quantitative traits. Based on the results of the cluster analysis, the okra
genotypes were grouped into three clusters according to their biochemical content,
as well as their quantitative and qualitative characteristics. Based on the results
of this analysis, eight genotypes were selected, namely Naila IPB with high
flavonoid content and DPPH antioxidants; Green Velvet, which was superior in
vegetative performance; Clemson, which had an advantage in fruit length; F7
ClemsonxStripe-3-23-4-27-50, which was superior in the number of locules. Red
okra genotypes were superior in DPPH antioxidant activity; C127 had an
advantage in early harvest age; and Red Hill Country was superior in
alphaglucosidase enzyme inhibition, weight, and fruit diameter. No association
was found between yield components and biochemical characters, except for
flowering and harvesting time.
The second experiment revealed that an interaction was observed between
genotype and harvest phase, resulting in different responses to biochemical
content at each phase for the eight genotypes. The 6 days after anthesis (DAA)
harvest phase produced the highest levels of total phenolic content, flavonoid
content, and antioxidant activity, as determined by the FRAP method. However,
antioxidant activity measured by the DPPH method revealed similar levels in the
6 and 9 DAA phases. Additionally, okra with a 9 DAA harvest phase produced
the maximum alpha-glucosidase enzyme inhibition. The Red Okra genotype
demonstrated superior phenolic content and FRAP antioxidant activity. The Red
Hill Country genotype excelled in flavonoid, DPPH, and FRAP antioxidant
activity. Naila IPB was superior in DPPH antioxidant activity, and F7
ClemsonxStripe-3-23-4-27-50 was superior in phenolic content, DPPH
antioxidant activity, and alpha-glucosidase enzyme inhibition. These results
reinforced the idea that harvest timing could be optimized for specific purposes,
such as antioxidant or antidiabetic potential.
The third experiment demonstrated that the role of gene interaction was
not evident in all yield and yield component characters, with the exception of fruit
number and harvest age. The antioxidant traits measured by the DPPH and FRAP
methods, as well as alpha-glucosidase enzyme inhibition, did not demonstrate a
gene interaction effect. The findings of this study indicated additive and dominant
gene action effects on several key parameters, including branch number, fruit
diameter, fruit number, and harvest time. Overdominance effects were observed
in the traits of number of nodes, number of branches, number of fruits, harvest
time, productivity, total phenolics, total flavonoids, DPPH, and FRAP antioxidant
activity. It was observed that all yield components and yield traits were controlled
by a single group of genes, with the exception of fruit length. Furthermore, the
expression of all biochemical content traits was governed by the activity of two
distinct gene groups. The broad-sense heritability estimates (h²bs) for yield
components, yield, and biochemical content traits indicated a broad category. The
narrow-sense heritability estimates (h²ns) in the high category were produced by
fruit weight, fruit length, fruit diameter, and all biochemical content traits..
The fourth experiment demonstrated that parents F7 exhibited the optimal
overall combining ability for the traits of number of nodes, number of branches,
number of fruits, and alpha-glucosidase enzyme inhibition. A comparison of the
overall combining ability for the traits of weight per fruit, fruit diameter, and
FRAP antioxidant activity revealed that parents RHC exhibited the most optimal
performance. GV was identified as the parent with the optimal DGU value for
fruit length and harvest age. In addition, OKM demonstrated the most optimal
overall combining ability for total phenolics and flavonoids, as well as DPPH
antioxidant activity. The F7 × Nai combination produced high specific combining
ability values for the number of fruits and productivity. In contrast, the OKM ×
Nai cross combination produced the best specific combining ability for fruit
length and fruit weight. The GV × F7 combination exhibited elevated specific
combining ability values for harvest age and alpha-glucosidase inhibition, while
the RHC × OKM combination demonstrated high specific combining ability for
total phenolics and DPPH antioxidant activity. It was not possible to prove the
relationship between genetic distance and genetic parameters, particularly
heterosis, in this population.
The fifth experiment demonstrated that the F7xNai hybrid exhibited
superiority in terms of the number of nodes, number of branches, number of fruits,
productivity, and high alpha-glucosidase enzyme inhibition. Consequently, the
F7xNai hybrid was recommended as a hybrid with high productivity and strong
antidiabetic effects, while the RHCxOKM hybrid was recommended as the hybrid
with the highest polyphenol content and antioxidant capacity. The fruit color
characteristics of the hybrids manifested as a more pronounced purple hue in
comparison to the green coloration observed in their parental species. The fruit
color characteristics exhibited in the F1 generation served as highly effective
visual markers during the preliminary selection process of breeding. | |
