Phosphorus Efficient Phenotype of Rice

Abstract

The ideal phenotype to cope with P deficiency is suggested to be a larger root system, both in terms of length and foraging area, coupled with a high capacity for P solubilization from compounds exuded from roots. Greater soil exploration results in a large number of roots in the top soil, longer roots in general with more cortical aerenchyma, more and longer root hairs, and a shift in mycorrhizal and bacterial colonization. However, these assumptions often result from experiments in highly controlled, sterile and soil-free conditions using model plants or single ecotypes where results are then extrapolated to all genotypes and plant species. In recent years this generalization has been questioned. Here, we summarize recent rice research analyzing the natural diversity of rice root systems under P deficiency. Interestingly, while some of the high yielding genotypes do show the expected, large root system phenotype, some have a surprisingly small root system-as little as a quarter of that of the large root system varieties-but achieve similar yield and P uptake under P deficiency. This effect has recently been termed root efficiency, which we discuss in this chapter in conjunction with root foraging traits.

Wheat Can Access Phosphorus From Algal Biomass as Quickly and Continuously as From Mineral Fertilizer

“…In a sand, dried algae biomass was not as effective (87%) compared to wet algae (107%), which even exceeded the mineral fertilizer treatment. Interestingly length and density of the root hairs and root diameters were significantly different between plants treated with algae and mineral fertilizer in the nutrient-poor and sandy soils (Schreiber et al, 2018), suggesting nutrient responses typical of mineral P treatments (Kant et al, 2018) and/or other soil solution signals (Sasse et al, 2018a). Schreiber et al (2018) suggest that algal biomass nutrients are more slowly acquired than those in mineral fertilizer and nutrient-rich soils.…”

How Sorghum Root Traits Can Contribute to Cereal Yield Increase

“…Root hair formation in these studies varied with environmental conditions, be it nutrient or water supply, or other soil properties, therefore it is likely that sorghum root hairs could be longer in less optimal conditions then the one they were grown in here. Studies on rice root type-dependent root hair formation also showed a high dependency on the growth media used [63,64].…”

The role of effluent water irrigation in the mineral absorption of aerobic rice varieties (Oryza sativa L.)

“…Altogether, one of the main indicators of 2 years of experience was that the aboveground biomass of both types of varieties accumulate a large amount of Na, influenced by environmental conditions and the amount of irrigation (treatments). The accumulation of Na in both genotypes is directly related to the fact that the Na transport mechanism is different from the transport mechanism of other (Ca, Mg, P, K) elements (Ochiai and Matoh 2002;Goel et al 2011;Tanoi et al 2011;Yang et al 2014;Sasaki et al 2016;Kant et al 2018). Although the main goal of plants is to protect the seeds from the surplus of this toxic element, depending on the amount of sodium, it can be accumulated in the aboveground biomass (leaves, stems) (Marschner 1995;Reddy et al 2017).…”