Leah Sta. Maria Dela Cruz. Development of dnd markers for the selection of pericarp color in rice. Master's Degree(Master of science in genetics). มหาวิทยาลัยแม่โจ้. สำนักหอสมุด . : Maejo University, 2018.
Development of dnd markers for the selection of pericarp color in rice
Abstract:
The red color in rice pericarp involves the complementary action of two genes, Re in chromosome 7 and Rd in chromosome 1. Red rice contains proanthocyanidin which has been proven to have human health benefits. The main objective of this study is to develop molecular markers that control the red color in rice pericarp in RD49 (white pericarp) and Red Hawm (red pericarp) population.
Indel-Rc-F/Indel-Rc-R primer was taken from Lim and Ha (2013) which resulted in polymorphism between RD49 and Red Hawm. PCR products of Indel-Rc-F/Indel-Rc-R marker used RD49 and Red Hawm as DNA templates were sent in DNA sequencing.
Re gene from the red indica cultivar Mudgo was aligned using CLUSTALX together with RD49 and Red Hawm sequences.
The sequence alignment of RD49 and Red Hawm using Indel-Rc-F/Indel-Rc-R marker was compared to the red pericarp color from the indica cultivar, Mudgo. Between Mudgo and Red Hawm, results showed a 100% similarity in both red pericarp. On the other hand, RD49 was similar to Red Hawm and Mudgo cultivars by 90.6%. This was because of the 14-bp deletion in RD49 (white pericarp) variety. Two primer pairs namely Rd-F1/Rd-R1 and Rd-F2/Rd-R2 were designed on the 5' UTR until 3' UTR of Rd gene of white japonica cultivar Nipponbare.
The PCR product of these primers was sent for DNA sequencing with RD49 and Red Hawm as DNA templates. Using CLUSTALX program, Rd gene of Nipponbare and the sequenced PCR product of RD49 and Red Hawm were aligned in which a 17-bp deletion was seen in RD49. The third primer, Rd-F3/Rd-R3, was designed flanking the 17-bp deletion in RD49. PCR product of Rd-F3/Rd-R3 primer was sent in DNA sequencing using RD49 and Red Hawm as DNA templates. Together with the Rd gene of the white pericarp japonica cultivar Nipponbare, RD49 had 91.2% similarity with Nipponbare, Red Hawm had 96.7% similarity with Nipponbare and RD49 had 89.3% similarity with Red Hawm. The results showing similarity percentage revealed that both markers can anneal in Rc/rc and Rd/rd genes of RD49 and Red Hawm. Only red and white pericarps were observed among the 187 F3, 108 BC1F3 and 102 BC2F3 seed generations to be phenotyped. No brown pericarp color was observed. This means that only the Rc gene controls red color of pericarp in this population. Chi-square test was computed in genotype as well as the phenotype whereby it followed the 1:2:1 and 3:1 ratio of the First Mendelian Law.
Therefore, Indel-Rc-F/Indel-Rc-R marker can be used in improving RD49 variety in the future resulting in producing red pericarp with high yield and hence the farmers can benefit.