Effects of the expression of random sequence clones on growth and transcriptome regulation in Escherichia coli

Comparative genomic analyses have provided evidence that new genetic functions can emerge out of random nucleotide sequences. Here, we apply a direct experimental approach to study the effects of plasmids harbouring random sequence inserts under the control of an inducible promoter. Based on data from previously described experiments dealing with the growth of clones within whole libraries, we extracted specific clones that had shown either negative or positive effects on relative cell growth. We analysed these individually with respect to growth characteristics and impact on the transcriptome. We find that candidate clones for negative peptides lead to growth arrest by eliciting a general stress response. Overexpression of positive clones, on the other hand, does not change the exponential growth rates of hosts, but they show a growth advantage over a neutral candidate clone when tested in direct competition experiments. Transcriptomic changes in positive clones are relatively moderate and specific to each clone. We conclude from our experiments that random sequence peptides are in-deed a suitable source for the de novo evolution of genetic functions.

Characteristics of growth, flowering and corm yield of iles-iles (Amorphophallus muelleri) genotypes at third growing period

Tajuddin M, Santosa E, Sopandie D, Lontoh AP. 2020. Characteristics of growth, flowering and corm yield of iles-iles (Amorphophallus muelleri) genotypes in third growing period. Biodiversitas 21: 570-577. Iles-iles (Amorphophallus muelleri Blume) is an emerging crop for producing glucomannan, and it is predominantly cultivated in agroforestry systems. The study aimed to evaluate characteristics of growth, flowering, and production of genotypes in the third growing period in order to develop new clones. The experiment used 2-year-old corm of ten genotypes, i.e. BKB, CF, CR, LSP, SB, SBM, SG-BKK, SGH, SR and STS. The corms were planted in June 2018 to May 2019 in the field under 45% artificial shading net. Plant growth was evaluated on weekly basis from bud emergence until dormant. Flowering rate was ratio the number of corms with flower to number of planted corms in each replication. Corm dry mass was measured after harvest, which was conducted at dormant stage at 46 weeks after planting. Candidate clone was selected from the highest total score of five criteria i.e. flowering rate, corm shape, corm healthiness, marketable yield, and total yield. Results demonstrated that genotypes exhibited variation in growth, flowering rates, and yield. Based on emerging time, three genotypes (SB, SGH, SG-BKK) were classified as early emergence, five genotypes (CF, CR, LSP, SBM, STS) as a medium, and two genotypes (BKB, SR) as the late emergence. All genotypes produced inflorescence at rate 1 to 52%, and 3 genotypes (CF, CR, STS) had flowering rate >20%. Five genotypes (CR, LSP, SBM, SGH, STS) had an average corm weight > 1500 g. CR and SBM genotypes produced the largest average corm weight, i.e., 2,509.33 g and 2,129.25 g, respectively, while the BKB produced the smallest one (912.94 g). All genotypes had similar dry mass content, i.e., 18.73-20.70%. The scoring evaluation recommended CR, SBM, and STS genotypes as candidates of new clones with productivity > 30 ton/ha. It needs further evaluation of selected clones in the farmer production field.

Yield Evaluation of Selected Clones Apomictic Iles-Iles (Amorphophallus muelleri Blume) on Second Growing Period

Increasing corm production of iles-iles (Amorphophallus muelleri Blume) through genetic improvement is important for increasing farmers’ income. However, the study on variety development is rarely reported. Here, yield evaluation of the second growing period was conducted at IPB Experimental Station Leuwikopo Farm, Bogor, Indonesia (-6.5647419, 106.7220331, 17.25z) from August 2017 to July 2018 in order to select candidate clone with high corm production. One-year-old corms of 21 F1 accessions were planted under 55% shading net with four replications. The parent population was set as a control. Results showed that accessions exhibited variation in corm size. The parent population produced corm ranged 622.3-908.3 g in weight (on average 764.2 g). The pooled accessions produced corm 180.7-1527.5 g in weight, corm diameter 71.0-145.8 mm, and corm height 46.6-87.6 mm. Nine accessions produced 5.91-99.88% higher average corms weight than the parent, i.e., BKB, BS, CF, CK, CR, DPG, DPP, SBM, and SHJ. Based on 30% as the basis of corm weight improvement, we concluded that five accessions, i.e., CK, CR, DPG, DPP, and SBM as prospective candidate clones. These accessions could be further evaluated in the third growing period to select best candidates of new variety of A. muelleri.Keywords: Agamosporous, Araceae, breeding strategy, new variety, productivity

Results of poplar clone testing in field experiments

Growth vigor of 7 poplar clones was researched, i.e. 5 candidate clones for registration (B-81, B-229, PE 19/66, 182/81 and 129/8) and 2 clonal cultivars (1-214 and "Pannonia") which had been registered earlier. The taxonomy of the study poplar clones was as follows: B-81 (Populus deltoides), B-229 (Populus deltoides), PE 19/66 (Populus deltoides), 182/81 (Populus deltoides), 129/81 (Populus x euramericana), 1-214 (Populus x euramericana) and "Pannonia" (Populus x euramericana). The research was performed in three field experiments established in 2002 on the area of the Forest Estate Sremska Mitrovica. Although the experiments were established with several planting spaces, the first information indicate that the candidate clone PE 19/66 had the greatest vigor on the optimal soil types (humofluviosol and fluvisol loamy form), while the candidate clone B-81 had the advantage on the less favored soil type (meadow black soil on loess alluvium). Based on the attained diameters and heights, it can be concluded that these are the successfully established plantations and that the candidate clones showed significant genetic potentials, which points to the fact that in future the production of poplar wood volume can be significantly increased.