Allelopathic Allelopathic impact of sorghum on weed management, yield and quality of maize under different seed rates

A field study was carried out to estimate the allelopathic potential of sorghum immature and mature plant extracts under various seed rates on weeds density and yield of maize cultivar Dadu Maize-I. The experiment contained of different weed control practices i.e., control (No weeding), various levels of sorghum immature and mature plant extracts, herbicides and hand weeding under various seed rates (20, 25, 30 & 35 kg per ha). The analysis of variance showed that various weed control practices demonstrated substantial decrease in weeds and caused increase in kernel yield over control. The application of sorghum immature extract @ 15 L per ha in combination with herbicide (Mesotrione Atrazine) @ 1.0 L per ha decreased effectively weed density (m-2) and dry biomass (g m-2) and resultantly produced superior growth and yield traits particularly kernel yield (t per ha) of maize. Sorghum mature plant extract @ 15 L per ha in integration with herbicide (Mesotrione Atrazine) @ 1.0 L per ha ranked 2nd in effectiveness of controlling weeds as well as increasing maize kernel yield (t per ha). As much as effect of seed rates is concerned, the least weed density (m-2) and greatest kernel yield (t per ha) were noticed in seed rate 35 kg per ha but optimal kernel yield (t per ha) was record in seed rate 30 kg per ha. Hence, the results suggested that combination of plant extracts and herbicide at reduced doses controlled weeds efficiently and optimum enhancement in kernel yield of maize was noticed at seed rate 30 kg per ha.

“Stately and Set Apart”

In Chapter 2, the members of Park Street Church in Boston (founded 1809) wrestle with the question of how to maintain their church’s historic identity without becoming a museum. The solution is an organic interpretation of progress. Park Street leaders believe that, just as a seed contains all the genetic information necessary to become a mature plant, healthy change unfold slowly and logically, according to a predictable trajectory, from a single point of origin. This chapter analyzes how the congregation’s understanding of progress is reflected in its preaching and musical repertoire. Just as God’s covenant with Abraham unites Israel and the New Testament church into a single people of God, so too does a musical “covenant” penned in 1810 by the church’s first musicians unite nineteenth- and twenty-first century congregations into a single Park Street Church.

Nanoparticle Cellular Internalization is Not Required for RNA Delivery to Mature Plant Leaves

Rapidly growing interest in nanoparticle-mediated delivery of DNA and RNA to plants requires a better understanding of how nanoparticles and their cargoes translocate in plant tissues and into plant cells. However, little is known about how the size and shape of nanoparticles influences transport in plants and use of their cargoes, limiting development and deployment of nanotechnology in plant systems. Here, we employ non-biolistically delivered DNA-modified gold nanoparticles (AuNP) spanning various sizes (5 – 20 nm) and shapes (spheres and rods) to systematically investigate their transport following infiltration into Nicotiana benthamiana (Nb) leaves. Generally, smaller AuNPs demonstrate more rapid, higher, and longer-lasting levels of association with plant cell walls compared to larger AuNPs. We observe internalization of rod-shaped but not spherical AuNPs into plant cells, yet surprisingly, 10 nm spherical AuNP functionalized with small-interfering RNA (siRNA) are most efficient at siRNA delivery and inducing gene silencing in mature plant leaves. These results indicate the importance of nanoparticle size in efficient biomolecule delivery, and, counterintuitively, demonstrate that efficient cargo delivery is possible and potentially optimal in the absence of nanoparticle cellular internalization. Our results highlight nanoparticle features of importance for transport within plant tissues, providing a mechanistic overview of how nanoparticles can be designed to achieve efficacious bio-cargo delivery for future developments in plant nanobiotechnology.

A new species of Cyanea Gaud. (Lobelioideae, Campanulaceae) from Maui, Hawai`i

Cyanea heluensis H. Oppenheimer, sp. nov., a new, narrowly distributed endemic species, is herein described and illustrated with line drawings and digital field photos. It is currently known from a single mature plant and is restricted to the upper Helu planeze on leeward Mauna Kahalawai, West Maui, Hawaiian Islands. It differs from all other species of Cyanea Gaudich. with its narrow, shallowly lobed leaves, gently curved muricate corollas, and undulate sepals caducous in fruit. A key to the new species and its congeners on Mauna Kahalawai is provided. Its conservation status and efforts to propagate the species are discussed.

Embryo CHH hypermethylation is mediated by RdDM and is autonomously directed in Brassica rapa

BackgroundRNA directed DNA methylation (RdDM) initiates cytosine methylation in all contexts, and maintains asymmetric CHH methylation (where H is any base other than G). Mature plant embryos show one of the highest levels of CHH methylation, and it has been suggested that RdDM is responsible for this hypermethylation. Because loss of RdDM in Brassica rapa causes seed abortion, embryo methylation might play a role in seed development. RdDM is required in the maternal sporophyte, suggesting that small RNAs from the maternal sporophyte might translocate to the developing embryo, triggering DNA methylation that prevents seed abortion. This raises the question whether embryo hypermethylation is autonomously regulated by the embryo itself or influenced by the maternal sporophyte.ResultsHere, we demonstrate that B. rapa embryos are hypermethylated in both euchromatin and heterochromatin and that this process requires RdDM. Contrary to current models, B. rapa embryo hypermethylation is not correlated with demethylation of the endosperm. We also show that maternal somatic RdDM is not sufficient for global embryo hypermethylation, and we find no compelling evidence for maternal somatic influence over embryo methylation at any locus. Decoupling of maternal and zygotic RdDM leads to successful seed development despite loss of embryo CHH hypermethylation.ConclusionsWe conclude that embryo CHH hypermethylation is conserved, autonomously controlled, and not required for embryo development. Furthermore, maternal somatic RdDM, while required for seed development, does not directly influence embryo methylation patterns.

Response of guava (Psidium guajava L.) softwood cuttings to paclobutrazol application in different rooting media

The scope of clonal propagation of guava (Psidium guajava L.) by soft wood cuttings collected from mature plant is described. The most successful media among those traditionally used and to identify promising alternatives was determined. Soft wood cuttings were done to determine the most successful medium and Paclobutrazol (PBZ) hormone concentration. Guava soft wood cuttings were treated with 0, 200, 400 and 600 mg/l PBZ solution and planted in three different rooting media (sand, silt and top soil) and rooted in low-tunnel. The cuttings were allowed to grow under low-tunnel for three months to assess the rooting capability and shooting competency. The study revealed that the species has a great potential for clonal propagation through soft wood cuttings.