scholarly journals Growth, yield and shelf-life of isopentenyltransferase (ipt)-gene transformed broccoli

2009 ◽  
Vol 89 (4) ◽  
pp. 701-711 ◽  
Author(s):  
L -F Chan ◽  
L. -F.O. Chen ◽  
H -Y Lu ◽  
C -H Lin ◽  
H -C Huang ◽  
...  

Loss of chlorophyll leading to floret yellowing limits the post-harvest lifespan of broccoli (Brassica oleracea L. var. italica Plenck). Cytokinins are known to delay floral yellowing of plants. A transgene construct pSG766A, which results in the expression of isopentenyltransferase (ipt), the key enzyme for cytokinin synthesis, has been developed in broccoli. Expression of the ipt transgene is triggered by the senescence-associated gene promoter (SAG-13). Three selfed T5 lines of ipt transformed broccoli (lines 101, 102 and 103) have been obtained through selection for single copy insertion, acceptable horticultural traits and transgene ipt activity. These three transgenic inbred lines were evaluated in the field during 2004-2007 to determine their growth, yield and shelf-life after harvest, relative to a non-transgenic inbred line (104) and the parental variety Green King. For most of the vegetative growth parameters measured, year-to-year variability exceeded line-to-line variability. Inbreeding had little impact on the appearance or yield potential of the broccoli lines. Head yields of the transgenic inbred lines 102 and 103 were comparable to the parental variety Green King, but were significantly higher than the non-transgenic inbred line 104, as lines 102 and 103 produced more plants with heavier flower heads. Cytokinin content in the form of isopentenyladenosine was relatively higher in the transgenic lines than in the two non-transgenic controls. When flower heads were stored at 25 ± 2°C, the period required to cause 50% floret yellowing was 7.5 and 8.5 d for the transgenic lines 102 and 103, respectively, compared with 5.6 d for the non-transgenic line 104, and 5.1 d for the parental variety Green King. This study showed that the ipt-transformed inbred lines of broccoli combined acceptable appearance and yields with enhanced shelf-life.Key words: Brassica oleracea L. var. italica Plenck, transgenic broccoli, isopentenyltransferase gene, genetic characterization, shelf-life

2014 ◽  
Vol 145 ◽  
pp. 77-85 ◽  
Author(s):  
Suhyoung Park ◽  
Mariadhas Valan Arasu ◽  
Min-Ki Lee ◽  
Jin-Hyuk Chun ◽  
Jeong Min Seo ◽  
...  

2021 ◽  
Vol 13 (2) ◽  
pp. 78
Author(s):  
L. Musundire ◽  
J. Derera ◽  
S. Dari ◽  
A. Lagat ◽  
P. Tongoona

Grain yield potential of new maize hybrid varieties across target environments contributes to the uptake of these varieties by farmers. Evaluation of single-cross hybrids developed from test crossing introgressed inbred lines bred for three distinct environments to elite tropical inbred line testers was carried out. The study’s objective was to assess grain yield stability and genotype adaptability of the single-cross hybrids across South African environments relative to adapted commercial hybrid checks. One hundred and twenty-two introgressed inbred lines developed using the pedigree breeding program were crossed to four tropical elite inbred line testers using line × tester mating design to obtain 488 experimental single cross hybrids. Subject to availability of adequate seed for evaluation, a panel of 444 experimental single-cross hybrids was evaluated using an augmented design in two experiments defined as Population A and B for the study’s convenience in South African environments. Data for grain yield (t/ha) performance for experimental single-cross hybrids and commercial check hybrids in Population A and B across environments and individual environments identified experimental single-cross hybrids that had significant comparable grain yield (t/ha) performance relative to best commercial check hybrid (PAN6Q445B) on the market. The selected experimental single-cross hybrids 225, 89, 246 and 43 (Population A) and 112 (Population B) also had a better average rank position for grain yield (t/ha) relative to best commercial check hybrid. These selected experimental single-cross hybrids had a grain yield (t/ha) advantage range of 0.9-6.7% for Population A and 7.3% for Population A and B, respectively, relative to the adapted commercial check hybrid. GGE biplot patterns for which won-where for Population A indicated that at Potchefstroom Research Station and Ukulinga Research Station experimental single-cross hybrids 127 and135 were the vertex (winning) hybrids. Cedera Research Station did not have a vertex hybrid for Population A. For Population B, experimental single-cross hybrids 112, 117 and 18 were the vertex hybrids at Cedera Research Station, Ukulinga Research Station and Potchefstroom Research Station, respectively. Experimental single-cross hybrid 257 was identified as ideal genotype for Population A, while experimental single-cross hybrid 121 in Population B was the ideal genotype. Ideal environments were also identified as Ukulinga Research Station for Population A, and Cedera Research Station for Population B. Average-environment coordination (AEC) view of the GGE biplot in Population A indicated that experimental single-cross hybrids 1 was highly stable across environments. In comparison, Population B experimental single-cross hybrid 161 was highly stable across environments. In conclusion, selected single-cross hybrids in the current study can also be advanced for further evaluation with a possibility for identifying high yielding and stable single-cross hybrids for variety registration and release in target environments in South Africa.


Author(s):  
Vivek Singh ◽  
Amit Kumar Singh ◽  
Tushar Raghuvanshi ◽  
Maneesh Kumar Singh ◽  
Vineet Singh ◽  
...  

Agronomy ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 116
Author(s):  
Hayoung Song ◽  
Myungjin Lee ◽  
Byung-Ho Hwang ◽  
Ching-Tack Han ◽  
Jong-In Park ◽  
...  

Global warming accelerates the development of high temperature (HT)- and high humidity (HH)-tolerant varieties. This is further facilitated by the identification of HTHH-tolerant genes and the development of molecular markers based on these genes. To identify genes involved in HTHH tolerance in cabbage (Brassica oleracea var. capitata), we performed RNA-seq analysis of two inbred lines, BN1 (HTHH-tolerant) and BN2 (HTHH-susceptible), and selected trehalose 6- phosphate phosphatase I-2 (BoTPPI-2) as one of the HTHH-tolerant-associated genes. We also developed a segregating F2 population from a cross between BN1 and BN2. RNA-seq results showed that BoTPPI-2 transcript levels were high in the HTHH-tolerant inbred line BN1, but not detectable in the HTHH-susceptible inbred line BN2. The expression pattern of BoTPPI-2 was not related to the expression of heat shock-related genes. Soft rot resistance, used as an indicator of HTHH tolerance, was higher in BN1 than in BN2. F2 individuals similar to BN1 with respect to phenotype appeared to be HTHH-tolerant, whereas BN2-types were susceptible to HTHH. Analysis of the genomic DNA revealed the presence of a long terminal repeat (LTR; ca. 4.6 kb) in the ninth intron of the BoTPPI-2_BN2 allele, thereby suppressing its transcription and exhibiting HTHH phenotype. Except for the LTR insertion, the sequence of BoTPPI-2_BN2 was almost identical to that of BoTPPI-2_BN1. On the basis of the LTR and BoTPPI-2 sequences, we developed a molecular marker to identify HTHH-tolerant genotypes and validated its efficiency using F2 individuals, inbred lines, and cultivars from diverse sources. The marker explained the genetic basis of HTHH tolerance in at least 80%, but not 100%, of the cabbage genotypes. Thus, additional markers associated with HTHH tolerance are needed for perfect selection.


Sign in / Sign up

Export Citation Format

Share Document