Combining ability and heterosis in plant improvement

Information on combining ability and heterosis of parents and crossings is crucial in breeding efforts. Genetic variety is crucial to the effectiveness of yield improvement efforts because it helps to broaden gene pools in any given crop population. The genotype's ability to pass the intended character to the offspring is referred to as combining ability. As a result, information on combining ability is required to determine the crossing pairs in the production of hybrid varieties. Heterosis is the expression of an F1 hybrid's dominance over its parents in a given feature, as measured not by the trait's absolute value, but by its practical use. To put it another way, heterosis is defined as an increase in the character value of F1 hybrids when compared to the average value of both parents. A plant breeder's ultimate goal is to achieve desirable heterosis (hybrid vigor). In a variety of crop species, heterosis has been widely employed to boost output and extend the adaptability of hybrid types. A crucial requirement for discovering crosses with significant levels of exploitable heterosis is knowledge of the quantity of heterosis in different cross combinations. Any crop improvement program's success is contingent on the presence of a significant level of genetic diversity and heritability. The lack of a broad genetic foundation is the most significant constraint to crop improvement and a major bottleneck in breeding operations. Heterosis is a critical factor in hybrid generation, particularly for traits driven by non-additive gene activity. To get the most out of heterosis for hybrid cultivar production, germplasm must be divided into distinct heterotic groups. Similarly, knowledge on genetic diversity is critical for hybrid breeding and population improvement initiatives because it allows them to analyze genetic diversity, characterize germplasm, and categorize it into different heterotic groupings. In general, general combining ability is used to detect a line's average performance in a hybrid combination, whereas specific combining ability is used to find circumstances where definite combinations perform better or worse than expected based on the mean performance of the lines involved.

Plant population is the function of grain yield of maize

A field experiment on hybrid maize with different plant population density was conducted at the Agronomy field of BARI, Joydebpur, Gazipur during the consecutive rabi season of 2019-2020 and 2020-2021. Five plant population density viz; T1= 66666 plants/ha (75cm × 20cm spacing: 6.67 plants/m2), T2= 83333 plants/ha (60cm × 20cm spacing:8.33 plants/m2), T3=100000 plants/ha (50cm × 20cm spacing:10 plants/m2), T4=125000 plants/ha (40cm × 20cm spacing:12.5 plants/m2) and T5=166666 plants/ha (30cm × 20cm spacing:16.67 plants/m2) were used in the experiment. LAI (leaf area index) and TDM (total dry matter) increased with the increase of plant population, those influenced grain yield of maize. The highest grain yield (10.12-10.78 t/ha) was recorded in T3 (100000 plants/ha) and the lowest (5.02-5.33t/ha) in T5 (166666 plants/ha) treatment. Functional relationship between plant population and grain yield of maize was established as Y = 2.0795x-0.1067x2; (R² = 0.92). The effect of plant population on the grain yield of maize could be explained 92% by the functional model. The co- efficient indicated that increase of one plant/m2 would increase grain yield at the rate of 2.0795 t/ha up to a certain limit. The estimated optimum plant population was 9.74 plants/m2 (974000 plants/ha) through functional model. Then the predicted maximum grain yield would be 10.13 t/ha at that optimum plant population of 9.74 plants/m2 (974000 plants/ha). There existed a good consistency between observed and predicted grain yield of maize (r=0.96 at p<0.01 and R2=0.97; using the developed functional model).

Anti-tuberculosis effects of different medicinal plants: A narrative review

The medicinal plants contain various chemical constituents which play an important role in the treatment of various diseases. The current review explained the scattered information on medicinal plants used in the treatment of tuberculosis. The review contains four medicinal plants (Allium sativum (L), Aloe vera (L), Acalypha indica (L) and Allium cepa (L)) having anti-tubeculosis effects. Moreover, six medicinal plants (Acorus calamus (L), Curcuma longa (L), Ephedra gerardiana, Glycyrrhiza glabra (L), Hygrophila auriculata, Papaver somniferum (L)) have been checked for their toxicological impacts in the treatment of tuberculosis.

Criterion is a touchstone in study of early angiosperms

Herendeen et al. set up a criterion identifying fossil angiosperms while they named five examples of fossil angiosperms in the same paper. Their normal-appearing operation, however, is fundamentally flawed: their exemplar fossil angiosperms did not honor their own criterion. This operation confused their proponents as well as other botanical researchers, hindering healthy progress in study on the origin of angiosperms. Herendeen et al. are obligated to give a plausible explanation for their perplexing operation. *Nature Plants has been informed of the problem in Herendeen et al. (2017). Nature Plants has refused to fix the problem due to reasons, according to the communication with Dr. Chris Surridge, an editor of Nature Plants.