The Effect of Microwave Treatment on Germination and Health of Carrot (Daucus carota L.) Seeds

The aim of the study was to evaluate the effect of microwave treatment on seed germination and health of carrot seeds using two seed lots naturally infected with the pathogens Alternaria dauci and A. radicina. Seeds of cv. Amsterdam and cv. Berlikumer varied in seed germination at the final count (50% and 29%, respectively), and seed infestation with A. radicina (38% and 5%, respectively). For treatment, seeds were placed in a Petri dish (dry treatment) or in a beaker with distilled water (wet treatment) and irradiated at power output levels 500, 650 and 750 W for 15, 30, 45, 60, 75, and 90 s. Germination and health were determined in treated and untreated (control) seed samples. Wet treatment controlled seed-borne fungi more efficiently than dry treatment. However, the exposure duration longer than 60 s frequently resulted in deterioration of seed germination. The highest seed germination in cv. Amsterdam was observed after microwave wet treatment at power output levels of 500 W for 75 s (81%), 650 W for 45 s (85%), and 750 W for 60 s (77%), whereas in the case of cv. Berlikumer this occurred when wet seeds were treated at 500 and 650 W for 60 s (46% and 43% respectively). Treating seeds soaked in water with microwaves for a period longer than 30 s, regardless of the power output, significantly decreased seed infestation with Alternaria spp. in both samples.

Ectopic expression of TaBG1 increases seed size and alters nutritional characteristics of the grain in wheat but does not lead to increased yields

Background Grain size is thought to be a major component of yield in many plant species. Here we set out to understand if knowledge from other cereals such as rice could translate to increased yield gains in wheat and lead to increased nitrogen use efficiency. Previous findings that the overexpression of OsBG1 in rice increased yields while increasing seed size suggest translating gains from rice to other cereals may help to increase yields. Results The orthologous genes of OsBG1 were identified in wheat. One homoeologous wheat gene was cloned and overexpressed in wheat to understand its role in controlling seed size. Potential alteration in the nutritional profile of the grains were also analyzed in wheat overexpressing TaBG1. It was found that increased TaBG1-A expression could indeed lead to larger seed size but was linked to a reduction in seed number per plant leading to no significant overall increase in yield. Other important components of yield such as biomass or tillering did not change significantly with increased TaBG1-A expression. The nutritional profile of the grain was altered, with a significant decrease in the Zn levels in the grain associated with increased seed size, but Fe and Mn concentrations were unchanged. Protein content of the wheat grain also fell under moderate N fertilization levels but not under deficient or adequate levels of N. Conclusions TaBG1 does control seed size in wheat but increasing the seed size per se does not increase yield and may come at the cost of lower concentrations of essential elements as well as potentially lower protein content. Nevertheless, TaBG1 could be a useful target for further breeding efforts in combination with other genes for increased biomass.

Knockdown NRPC2, 3, 8, NRPABC1 and NRPABC2 Affects RNAPIII Activity and Disrupts Seed Development in Arabidopsis

RNA polymerase III (RNAPIII) contains 17 subunits forming 4 functional domains that control the different stages of RNAPIII transcription and are dedicated to the synthesis of small RNAs such as 5S rRNA and tRNAs. Here, we identified 23 genes encoding these subunits in Arabidopsis (Arabidopsis thaliana) and further analyzed 5 subunits (NRPC2, NRPC3, NRPC8, NRPABC1, and NRPABC2) encoded by 6 genes with different expression patterns and belonging to different sub-complexes. The knockdown of these genes repressed the expression of 5S rRNA and tRNAs, causing seed developmental arrest at different stages. Among these knockdown mutants, RNA-seq analysis revealed 821 common differentially expressed genes (DEGs), significantly enriched in response to stress, abscisic acid, cytokinins, and the jasmonic acid signaling pathway. Weighted gene co-expression network analysis (WGCNA) revealed several hub genes involved in embryo development, carbohydrate metabolic and lipid metabolic processes. We identified numerous unique DEGs between the mutants belonging to pathways, including cell proliferation, ribosome biogenesis, cell death, and tRNA metabolic processes. Thus, NRPC2, NRPC3, NRPC8, NRPABC1, and NRPABC2 control seed development in Arabidopsis by influencing RNAPIII activity and, thus, hormone signaling. Reduced expression of these subunit genes causes an insufficient accumulation of the total RNAPIII, leading to the phenotypes observed following the genetic knockdown of these subunits.

The Use of Coherent Laser Stimulation of Seeds and a Fungal Inoculum to Increase the Productivity and Health of Soybean Plants

The laser stimulation of seeds is regarded as a modern method of seed enhancement. Our study evaluated the productivity and health of soybean plants resulting from the coherent irradiation of seeds and irradiation of an arbuscular mycorrhizal fungi (AMF) inoculum. The two-factor pot experiment took into account (1) the type of irradiated biological material (seeds, AMF inoculum, and seeds and inoculum) and (2) the means of irradiation (red laser—LR, blue laser—LB, red and blue laser—LR + LB, and control). Seed weight per plant, pod number per plant, root weight, the Fv/Fm fluorescence parameters, and the health status of the aboveground and underground parts of the plants were assessed. Stimulation with a laser light was shown to have a positive effect on the productivity and health of soybean plants. Significantly better effects can be obtained by stimulating the seeds alone. The stimulation of seeds treated with AMF inoculum slightly reduced the productivity of the plants. However, with regards to the conditions of plants, the treatment of seeds with AMF inoculum and laser irradiation was shown to reduce the incidence of Septoria brown spots.

Effect of Seed Treatment with Chemicals and Plant Growth Regulators on Growth and Yield Attributing Traits of Indian Mustard (Brassica juncea L.) Variety: Pusa Bold

The Experiment was conducted in the field of Department of Genetics and Plant Breeding, Sam Higginbottom University of Agriculture, Technology and Sciences, Prayagraj (U.P.) during Rabi season 2020-2021, in order to standardize the suitable pre- sowing seed treatment for Mustard. Different pre- sowing seed treatments with control (Unhardened) were evaluated viz., T0– Control,T1- Mg(No3)2 @ 0.1%,T2- Mg(No3)2 @ 0.3%,T3- Mg(No3)2 @ 0.5%,T4- Ca(No3)2 @ 0.1%,T5- KNO3 @ 0.5%,T6- Mg(So4)2 @ 0.1%,T7- Mg(So4)2 @ 0.3%,T8- Mg(So4)2 @ 0.5%,T9- GA3 @ 25ppm,T10- GA3 @ 50ppm,T11- GA3 @ 75ppm,T12- PEG6000 @ 25ppm. It was found that the all pre-sowing seed treatments showed significance difference with control. Seed treatment with KNO3 @ 0.5% found to be highest in field emergence and yield attributes of Mustard and it was followed by GA3 @ 25ppm and Mg(No3)2 @ 0.1%. Pre- sowing seed treatment with KNO3 @ 0.5% and GA3 @ 25 ppm showed maximum increase yield of mustard seeds and found to be lowest in control seeds. Pre-sowing seed treatments of the mustard seeds in which KNO3 @ 0.5% gave best result to enhanced germinability, seed vigour, seed yield and yielding attributes. These conclusions are based on the results of six months investigation and therefore further investigation is needed to arrive at valid recommendations.

Combinations of maternal-specific repressive epigenetic marks in the endosperm control seed dormancy

Polycomb Repressive Complex 2 (PRC2)-mediated trimethylation of histone H3 on lysine 27 (H3K27me3) and methylation of histone 3 on lysine 9 (H3K9me) are two repressive epigenetic modifications that are typically localized in distinct regions of the genome. For reasons unknown, however, they co-occur in some organisms and special tissue types. In this study, we show that maternal alleles marked by H3K27me3 in the Arabidopsis endosperm were targeted by the H3K27me3 demethylase REF6 and became activated during germination. In contrast, maternal alleles marked by H3K27me3, H3K9me2, and CHG methylation (CHGm) are likely to be protected from REF6 targeting and remained silenced. Our study unveils that combinations of different repressive epigenetic modifications time a key adaptive trait by modulating access of REF6.

GmFULa improves soybean yield by enhancing carbon assimilation without altering flowering time or maturity

Key message GmFULa improved soybean yield by enhancing carbon assimilation. Meanwhile, different from known yield-related genes, it did not alter flowering time or maturity. Abstract Soybean (Glycine max (L.) Merr.) is highly demanded by a continuously growing human population. However, increasing soybean yield is a major challenge. FRUITFULL (FUL), a MADS-box transcription factor, plays important roles in multiple developmental processes, especially fruit and pod development, which are crucial for soybean yield formation. However, the functions of its homologs in soybean are not clear. Here, through haplotype analysis, we found that one haplotype of the soybean homolog GmFULa (GmFULa-H02) is dominant in cultivated soybeans, suggesting that GmFULa-H02 was highly selected during domestication and varietal improvement of soybean. Interestingly, transgenic overexpression of GmFULa enhanced vegetative growth with more biomass accumulated and ultimately increased the yield but without affecting the plant height or changing the flowering time and maturity, indicating that it enhances the efficiency of dry matter accumulation. It also promoted the yield factors like branch number, pod number and 100-seed weight, which ultimately increased the yield. It increased the palisade tissue cell number and the chlorophyll content to promote photosynthesis and increase the soluble sugar content in leaves and fresh seeds. Furthermore, GmFULa were found to be sublocalized in the nucleus and positively regulate sucrose synthases (SUSs) and sucrose transporters (SUTs) by binding with the conserved CArG boxes in their promoters. Overall, these results showed GmFULa promotes the capacity of assimilation and the transport of the resultant assimilates to increase yield, and provided insights into the link between GmFULa and sucrose synthesis with transport-related molecular pathways that control seed yield.

Pathogens associated with grain discolouration and their management in paddy (Oryza sativa L.)

Grain discoloration complex disease of rice is an emerging threat to rice crop all over the world and it acquires particular importance as it results in qualitative loss of harvested crop. So the present study was carried out to identify different fungi associated with disease and their management. The discoloured seed samples were collected from different farmer’s field during survey. Totally seven fungi including both saprophytic as well as pathogenic were isolated and identified from both blotter and potato dextrose agar method viz., Curvularia lunata (36.30 %), Helminthosporium oryzae (25.6 %), Fusarium moniliformae (19.6 %), Colletotrichum gloeosporioids (8.1 %) and Alternaria spp. (7.01 %) were predominantly associated with discoloured paddy seeds. Other saprophytic fungi like Aspergillus spp. (16.6 %) and Rhizopus spp. (12.1 %) were frequently observed. Similarly among the eleven treatment including control, seed treatment with carbendazim 50 WP (2 g kg-1) with two sprays of tebuconazole 250 EC at 0.1 per cent concentration and tricyclazole 18 % + mancozeb 62 % WP at 0.2 per cent first spray during flowering stage and second spray during 15 days after first spray reducing discoloured panicle by 61.46 per cent and 59.92 per cent, respectively.

Pueraria montana var. lobata (kudzu).

P. montana, formerly known as P. lobata, is widely known in the USA as 'kudzu' is native to East Asia. However, it does not appear to be a significant problem anywhere except in south-eastern USA where it was extensively planted in the 1930s and 1940s for erosion control. Seed dispersal appears to be minor but vegetative growth in subtropical areas can be substantial, up to 18 m per growing season. It is a climbing vine and kills vegetation by completely smothering it, and it will also entirely cover telegraph poles and buildings if left to itself. Once introduced it is difficult to control, especially in forest and marginal habitats. There are three varieties, although only var. lobata is so far known to be invasive, in the USA.