Forage potential of Urochloa genotypes by using leaf anatomy

Abstract

The digestibility potential of leaves from forages depends on the amount of nutrition in their tissues, with low lignin deposition in the cell wall, mainly parenchyma and phloem. This research evaluated the leaf structure of different Urochloa genotypes and discussed its potential for evaluating digestibility. The cultivars U. brizantha, U. decumbens, U. ruziziensis and three clones of U. ruziziensis (1, 95 and 97), which are under development in breeding programs, were evaluated. Plants were grown under the recommended culture conditions for the Urochloa species. Plants were cut 60 days after sowing, and leaves were collected at 15 days of regrowth. Leaves were fixed in FAA 70 and further stored in 70% ethanol until being submitted to the usual microtechniques for the preparation of microscopy slides. The area of the tissues from the interveinal and midrib regions was measured using ImageJ software, and their proportions were calculated. In the interveinal region, the proportion of chlorophyll parenchyma was greater for U. decumbens and the Clone 1 genotypes. Urochloa brizantha and clones 95 and 97 showed a higher proportion of the vascular bundle compared to U. ruziziensis, U. decumbens and Clone 1. The proportion of the ground parenchyma in the midrib was greater in U. brizantha, Clone 95 and Clone 97. Thus, it can be concluded that the Clone 1 genotypes (from U. ruziziensis) showed leaf tissues (parenchyma and phloem) with higher digestibility potential; in addition, U. brizantha and U. decumbens showed a high percentage of xylem and sclerenchyma, which reduces their quality as forage.

Nutritive value and anatomical characterization from Pennisetum purpureum genotypes

“…Batistoti et al (2012) corroborated this observation. Mauri et al (2019) pointed out that, as there is a significant presence of xylem and sclerenchymatous tissue, these overcome the tissue with higher digestion potential and reduce the forage potential. Forages with higher proportions of xylem and sclerenchymatous tissue have a higher lignin deposition on the cell walls.…”

Leaf anatomy of Urochloa brizantha and Urochloa ruziziensis (Poaceae) plants subjected to different fertilization management practices

“…U. brizantha showed higher thickness of the leaf blade, interveinal chlorenchyma, and adaxial and abaxial cuticle than U. ruziziensis (Table 1). Mauri et al (2019) reported distinct foliar anatomical structures to those two species, with thicker ground parenchyma occurring in the leaf blade mid region of U. brizantha than in that of U. ruziziensis. Furthermore, we found a thicker abaxial epidermis on leaves of U. brizantha; it is possible that the cuticle, a lipid-impregnated epidermal structure, is also thicker in that species.…”

“…Thus, in both species the alterations found on the internal leaf structure were due to factors acting individually (Figures 1 and 2). However, when we compare tissue structural organization between the two species without considering the fertilization treatment, U. brizantha and U. ruziziensis show distinct structures, which are due to the natural anatomical variation found among different species, without the interference of external environmental factors (Mauri et al, 2019). In that sense, U. brizantha showed higher thickness of the leaf blade, regular homogenous parenchyma, and adaxial and abaxial cuticle than U. ruziziensis, as revealed by morphometric analysis (Figures 1A and 2A).…”

Cattle preference in Paspalum atratum and its relationship with morphological and anatomical leaf characteristics

“…The material was fixed and dehydrated in acetonic series, dried to the critical point, and metalized with gold/palladium. Images from the midrib, interveinal (Mauri et al., 2019), and marginal regions of the transverse sections of the leaf were analyzed with ImageJ software (Schneider et al., 2012). Digital photomicrographic images were evaluated to determine the area of tissues as follows: the epidermis, the bulliform cells, the sum of parenchyma and chlorenchyma, the sum of xylem and sclerenchyma (lignified tissues), and the sum of the areas of the bundle sheath.…”